Manual Therapy Journal - Volume 13, Issue 2, Pages 91-180 (April 2008)

VOLUME 13 NUMBER 2 PAGES 91–180 April 2008 Editors International Advisory Board Ann Moore PhD, GradDipPhys, FCSP, Cer...

Author: Editors: Ann Moore and Gwen Jull

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VOLUME 13 NUMBER 2 PAGES 91–180 April 2008

Editors

International Advisory Board

Ann Moore PhD, GradDipPhys, FCSP, CertEd, FMACP Clinical Research Centre for Health Professions University of Brighton Aldro Building, 49 Darley Road Eastbourne BN20 7UR, UK

K. Bennell (Victoria, Australia) K. Burton (Hudders¢eld, UK) B. Carstensen (Frederiksberg, Denmark) M. Coppieters (Queensland, Australia) E. Cruz (Setubal Portugal) L. Danneels (Mar|¤ akerke, Belgium) S. Durrell (London, UK) S. Edmondston (Perth, Australia) J. Endresen (Flaktvei, Norway) L. Exelby (Biggleswade, UK) T.W. Flynn (Denver, CO, USA) J. Greening (London, UK) C. J. Groen (Utrecht,The Netherlands) A. Gross (Hamilton, Canada) T. Hall (West Leederville, Australia) W. Hing (Auckland, New Zealand) M. Jones (Adelaide, Australia) S. King (Glamorgan, UK) B.W. Koes (Amsterdam,The Netherlands) J. Langendoen (Kempten, Germany) D. Lawrence (Davenport, IA, USA) D. Lee (Delta, Canada) R. Lee (Brighton, UK) C. Liebenson (Los Angeles, CA, USA) L. Ma¡ey-Ward (Calgary, Canada) E. Maheu (Quebec, Canada) C. McCarthy (Coventry, UK) J. McConnell (Northbridge, Australia) S. Mercer (Queensland, Australia) D. Newham (London, UK) J. Ng (Hung Hom, Hong Kong) S. O’Leary (Queensland, Australia) L. Ombregt (Kanegem-Tielt, Belgium) N. Osbourne (Bournemouth, UK) M. Paatelma (Jyvaskyla, Finland) N. Petty (Eastbourne, UK) A. Pool-Goudzwaard (The Netherlands) M. Pope (Aberdeen, UK) G. Rankin (London, UK) D. Reid (Auckland, New Zealand) A. Rushton (Birmingham, UK) C. Shacklady (Manchester, UK) M. Shacklock (Adelaide, Australia) D. Shirley (Lidcombe, Australia) V. Smedmark (Stenhamra, Sweden) W. Smeets (Tongeren, Belgium) C. Snijders (Rotterdam,The Netherlands) R. Soames (Dundee, UK) P. Spencer (Barnstaple, UK) M. Sterling (St Lucia, Australia) P. Tehan (Victoria, Australia) M. Testa (Alassio, Italy) M. Uys (Tygerberg, South Africa) P. van der Wur¡ (Doorn,The Netherlands) P. van Roy (Brussels, Belgium) B.Vicenzino (St Lucia, Australia) H.J.M.Von Piekartz (Wierden,The Netherlands) M.Wallin (Spanga, Sweden) M.Wessely(Paris, France) A.Wright (Perth, Australia) M. Zusman (Mount Lawley, Australia)

Gwendolen Jull PhD, MPhty, Grad Dip ManTher, FACP Department of Physiotherapy University of Queensland Brisbane QLD 4072, Australia Associate Editor’s Darren A. Rivett PhD, MAppSc, (ManipPhty) GradDipManTher, BAppSc (Phty) Discipline of Physiotherapy Faculty of Health The University of Newcastle Callaghan, NSW 2308, Australia Tim McClune D.O. Spinal Research Unit. University of Hudders¢eld 30 Queen Street Hudders¢eld HD12SP, UK Editorial Committee Masterclass Editor Karen Beeton PhD, MPhty, BSc(Hons), MCSP MACP ex o⁄cio member Associate Head of School (Professional Development) School of Health and Emergency Professions University of Hertfordshire College Lane Hat¢eld AL10 9AB, UK Case reports & Professional Issues Editor Je¡rey D. Boyling MSc, BPhty, GradDipAdvManTher, MCSP, MErgS Je¡rey Boyling Associates Broadway Chambers Hammersmith Broadway LondonW6 7AF, UK Book Review Editor Raymond Swinkels MSc, PT, MT Ulenpas 80 5655 JD Eindoven The Netherlands

Visit the journal website at http://www.intl.elsevierhealth.com/journals/math doi:10.1016/S1356-689X(08)00040-4

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Manual Therapy 13 (2008) 91–92 www.elsevier.com/locate/math

Editorial

Educator skills for musculoskeletal therapy practice: Do we use these skills effectively and how and when are they used? Any multi-modal package of care for the patient with a musculoskeletal disorder includes education and advice. If patients are asked their expectations of musculoskeletal therapy, these usually include pain relief, but they will also indicate that they want information about what is causing their problem, what the therapist will do about it, what they can do to manage the problem and how they can prevent the problem happening again. If therapists are asked what they expect to happen in the treatment session, they will say they will actively treat the problem (commonly the pain element and/or limitation of movement) and will give education and advice. Indeed in standardised data collection projects carried out over recent years, joint mobilisation, active exercises and education/advice are the three most commonly combined treatment strategies employed in musculoskeletal physiotherapy outpatient settings. If musculoskeletal therapists are asked what would constitute education and advice for a particular problem, the responses will vary markedly, from a detailed explanation of the problem and possible causative elements, details of numbers of treatments which may be necessary, an explanation of assessment and treatment processes and procedures, instructions and clear advice about self-management including, as appropriate, details of home exercises, pain relieving agents, physical activity, weight loss, postural advice and sports advice. The advice might also include how to progress exercises and of course information will be included about possible effects and side effects of any treatment contemplated. This educational approach might constitute the exemplar, but on the other hand some therapists, if asked what they intend to do as part of their education and advice component, will say ‘well I’ll show the patient a few exercises’ or ‘I’ll tell them how to control pain’ or ‘I’ll give them advice about work activities’. The variation in practice is quite amazing and potentially worrying. The basic concepts in good educational practice are addressed within a education curriculum model. In outline, the model consists of planning, implementing, 1356-689X/$ - see front matter r 2008 Published by Elsevier Ltd. doi:10.1016/j.math.2008.02.006

assessing and evaluating learning processes. This module is used universally in formal educational situations such as higher education institutes and schools. Yet how many of us truly utilise this model in clinical practice and therefore, how do we know if the knowledge and skills addressed in a treatment session in relation to patient education have indeed been learnt by our patients? How often do clinicians assess whether learning has taken place at all? Although patients are often surveyed about satisfaction with the treatment they have received, how often are they asked to evaluate the educational component? The answer is probably never! The clinician’s response is often ‘well we can’t sit our patients down to do an exam can we?’ There are a number of factors to reﬂect upon. Firstly, systematic reviews indicate that education has evidence to support its effectiveness and, considering that this aspect of care can be quite unstructured and variable, this is surprising, but further indicates the power of this aspect of the multi-modal treatment package. Therapists tend to speak of education as an add-on, but in truth, for the patient, this is often seen as a major component of required care which is quite inﬂuential in their recovery. We often speak as a group of our commitment to patients’ self-management, but is this real or are we simply being politically correct? At this time, when all professions are being challenged about their evidence base, it is time to focus strongly on all aspects of our treatment strategies and focus on what patients tell us they want and which we perceive they can offer them. We have a complex box from which we pull modalities. Perhaps it is now time for our box to be fully opened and for components of multi-modal care to be rationalised into a more distinct ﬁling system. Perhaps this could be in a system of ‘‘must-do boxes’’ for each component, or perhaps green boxes which indicate must-do treatment/education approaches, for example, there could be a must-do box for pain relieving strategies, another for rehabilitation strategies and another for education and advice strategies.

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Within the education and advice must-do box, perhaps the following should be included: education and advice about the problem (i.e. physiotherapy diagnosis, possible causative factors), some details of the possible structures causing the problem, information about how agreed goals will and can be fulﬁlled, what the overall multi-modal treatment package will consist of, how long it will take, what it can do or not do, and what are the possibly adverse events. Tied in with this could be patient consent if necessary and appropriate. Other education should include what will the treatment feel like and how will it be given; some details of selfmanagement including discussion of lifestyle, diet, physical activity, information about speciﬁc strategies related to the treatment. For example, what can the patient do to enhance pain relief, functional restoration, increasing their strength, increasing their mobility, and how can they adapt these self-management strategies in terms of dosage and frequency. The patient also requires information on what they can do if the problem happens again. In this package it would also be important to address the value of the individual patient taking control of their problem, i.e. enabling their empowerment and the importance of them changing their lifestyle/habits if these are deemed to be causing the problem. Hence one can be aiding patients’ self-efﬁcacy. Importantly, an education and advice package should be given in a form that suits the patient, i.e. the learner. This may vary according to the individual’s learning style, i.e. do they respond better to verbal instructions, to picture format, to booklets, or are they better looking at DVDs or listening to CDs? Whether learning has taken place or not must be assessed. If it was worth spending the time on delivering this educational package, then it is worth the time and effort in assessing whether learning has actually taken place and this can be by discussion, through patient

demonstration, through a tick-box questionnaire, or even through a patient-completed diary. Finally, true to good educational practice, it behoves the educator to evaluate the learning experience from the perspective of the learner and also from their own perspectives, i.e. were the instructions clear, did the learner/patient fully understand the instructions given, could they perform the tasks set easily and if not why not? How did they feel about the therapist as an educator? Were the explanations clear, could they have been carried out in a different way which would have been more constructive or would the instructions have been better given in a group setting? All these things will help the therapist to improve their educational performance. Why have we written this Editorial at all? Musculoskeletal therapists do a great deal of excellent work, but we perhaps don’t reﬂect on what we do sufﬁciently. Patients and other health professionals don’t necessarily know what we do and how well we can do it. In addition, musculoskeletal therapists have much to offer outside the musculoskeletal clinic. For example, there is a great role for musculoskeletal therapists in public health where we can practise specialist prevention rather than just interventions. We may have very valuable skills that we can bring to these fora and so let us do it before we lose the opportunities to other professions who are less well equipped to deal with many scenarios that musculoskeletal therapists are indeed very comfortable with. Let us educate as we say we do, but let us do it better, let’s be more focused and let’s use these skills more widely. Ann Moore, Gwen Jull (Editors) University of Brighton, Aldro Building, 49 Darley Road, Eastbourne, East Sussex, BN20 7UR, UK E-mail address: [email protected] (A. Moore)

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Masterclass

Physical and psychological aspects of whiplash: Important considerations for primary care assessment Michele Sterlinga,b,, Justin Kenardya a

Centre of National Research on Disability and Rehabilitation Medicine (CONROD), The University of Queensland, Mayne Medical School, Herston Road, Herston, Qld. 4066, Australia b Division of Physiotherapy, The University of Queensland, Qld. 4072, Australia Received 15 August 2007; accepted 16 November 2007

Abstract Whiplash is a heterogenous and in many, a complex condition involving both physical and psychological factors. Primary care practitioners are often the ﬁrst healthcare contact for individuals with a whiplash injury and as such play an important role in gauging prognosis as well as providing appropriate management for whiplash injured patients. It is imperative that factors associated with poor outcome are recognized and managed in the primary care environment at the crucial early acute stage post injury. This paper outlines the heterogeneity of the whiplash condition in terms of both physical (particularly the sensory presentation) and psychological characteristics and the relationships between these features. The clinical assessment of these factors will be explored as well as direction for appropriate early interventions. An early co-ordinated inter-professional management approach, particularly in patients with a complex clinical presentation involving central hyperexcitability and symptoms of posttraumatic stress will be required. Crown Copyright r 2007 Published by Elsevier Ltd. All rights reserved. Keywords: Whiplash associated disorders; Central hyperexcitability; Posttraumatic stress; Assessment

1. Introduction The development of persistent pain and other symptoms following whiplash injury during a motor vehicle crash (MVC) is common. Whilst it has generally been stated that only a minority of injured individuals will make the transition to chronic pain and disability (Bogduk and McGuirk, 2006), recent Australian data indicate that the prognosis may not be so favourable. In these studies approximately 60% of people continued to report pain and associated disability 6 months and 2 years after the original MVC (Rebbeck et al., 2006; Sterling et al., 2005, 2006). Whiplash is a signiﬁcant Corresponding author at: Centre of National Research on Disability and Rehabilitation Medicine (CONROD), The University of Queensland, Mayne Medical School, Herston Road, Herston, Qld. 4066, Australia. Tel.: +61 7 3365 5344; fax: +61 7 3346 4603. E-mail address: [email protected] (M. Sterling).

public health problem with most of the social and ﬁnancial burden arising from those who develop chronic pain and disability (Rebbeck et al., 2006). Whiplash is a heterogenous condition. The presence of certain physical and psychological characteristics (hyperalgesia, movement loss, posttraumatic stress symptoms (PTSS), moderate/severe levels of pain and disability) demonstrates a complex clinical picture in some (Sterling, 2004). This clinical presentation reﬂects multifaceted mechanisms underlying whiplash pain, including augmented central pain processing mechanisms in association with posttraumatic stress (Sterling and Kenardy, 2006). The early presence of these factors is predictive of poor functional recovery from the injury (Kasch et al., 2001; Sterling et al., 2006). This suggests that early intervention comprising management options to address these factors may be necessary in order to prevent the transition to chronic pain and disability in ‘at risk’ patients.

1356-689X/$ - see front matter Crown Copyright r 2007 Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2007.11.003

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Primary care practitioners are often the ﬁrst healthcare contact for individuals with a whiplash injury. An important role for clinicians is to not only provide ‘treatment’ but also to attempt to gauge the prognosis for the patient. This will alert the clinician that a more concerted approach to management may be necessary, one that could involve input from other health care providers. Should such an approach be deemed appropriate then the primary care clinician should aim to coordinate care between the various professionals involved in the patient’s management. It is imperative that factors associated with poor outcome are recognized and managed in the primary care environment at the crucial early acute stage post injury. Musculoskeletal clinicians play an important role in this regard. This paper will outline the heterogeneity of the whiplash condition in terms of both physical and psychological characteristics and the relationships between these features. It will outline how these factors may be recognized in the primary care environment and the implications for management.

2. The heterogeneity of whiplash—the physical presentation Motor and sensori-motor dysfunction, including movement loss, altered cervical and shoulder girdle muscle recruitment patterns, kinaesthetic deﬁcits and balance loss have been identiﬁed in both the acute and chronic stages of the whiplash condition (Dall’Alba et al., 2001; Nederhand et al., 2002; Sterling et al., 2003a; Treleaven et al., 2003, 2005). Most of the motor deﬁcits are present to various degrees in whiplash injured individuals irrespective of pain and disability levels and level of recovery (Sterling et al., 2003b; Treleaven et al., 2003). Additionally, these features may not be unique to whiplash and have also been identiﬁed in chronic neck pain of insidious (nontraumatic) onset (Jull et al., 2004; Field et al., 2007). Furthermore, treatments directed at rehabilitating motor dysfunction and improving general movement show only modest effects on pain and disability (Jull et al., 2007b; Stewart et al., 2007). Together these ﬁndings suggest that motor deﬁcits, although present, may not play a key role in the development of chronic symptoms following whiplash injury. This is not to say that treatment directed at ameliorating motor dysfunction should not be provided to whiplash injured people. Rather that the identiﬁcation of such impairments may not equip the clinician with useful information on either prognosis or treatment responsiveness. In contrast to the apparently uniform presence of motor dysfunction, the sensory presentation is a feature that differentiates whiplash from less severe neck pain conditions and whiplash sub-groupings. There is now

consistent evidence of sensory disturbances indicative of central nervous system hyperexcitability as an important feature of some whiplash injured people and these ﬁndings are summarized in Table 1. The presence of central hyperexcitability is not unique to whiplash, with other painful conditions including ﬁbromyalgia, tension-type headache and migraine also manifesting such signs (Yunus, 2007). However, it is not a phenomenon universal to all musculoskeletal conditions or to all forms of neck pain. Scott et al. (2005) recently showed that insidious onset chronic neck pain demonstrated a very different sensory presentation. The hyperalgesia of this neck pain group was conﬁned locally to the cervical spine with no widespread hypersensitivity that would indicate more profound central nervous system changes. Whiplash sub-groups can also be identiﬁed based on their sensory presentation.

Table 1 Studies supporting the presence of central hyperexcitability in WAD: whiplash associated disorders Study

Findings

Study cohort

Sheather-Reid and Cohen (1998) KoelbaekJohansen et al. (1999)

Lowered pain threshold and pain tolerance to electrical stimulation-neck Widespread pain responses following injection of intramuscular hypertonic saline Lowered pain thresholds for electrical stimulation—neck and lower limbs Sensory disturbance in trigeminal distribution Mechanosensitivity to brachial plexus provocation manoeuvres Lowered pressure pain thresholds throughout body areas Hypersensitive responses to brachial plexus provocation test Pain on non noxious stimulation (vibration) Hyperalgesia to heat and cold stimuli Cold hyperalgesia, sympathetic disturbances predictive of poor outcome Decreased threshold for activation of ﬂexor withdrawal reﬂex Mechanical and thermal hyperalgesia—present in chronic WAD but not idiopathic neck pain Reduced cold pressor pain tolerance associated with poor recovery

Chronic neck pain including WAD Chronic WAD

Curatolo et al. (2001) Sterner et al. (2001) Ide et al. (2001) Sterling et al. (2002b) Sterling et al. (2002c) Moog et al. (2002)

Sterling et al. (2003a, 2005) Banic et al. (2004) Scott et al. (2005)

Kasch et al. (2005)

Chronic WAD

Chronic WAD Chronic WAD

Chronic WAD

Chronic WAD

Chronic WAD

Acute to chronic WAD Chronic WAD

Chronic WAD and idiopathic neck pain Acute to chronic WAD

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A sub-group with widespread sensory hypersensitivity indicative of central hyperexcitability can be identiﬁed from very soon after injury and it is this sub-group who show poor functional recovery (Sterling et al., 2003a, 2005). The other whiplash injured participants in this study showed a similar presentation to insidious onset neck pain—that is the presence of local cervical hyperalgesia with little evidence of more widespread changes (Sterling et al., 2003a). It is not clear why some people appear to develop central hyperexcitability following whiplash injury but there is a relationship between this phenomena and reported levels of pain and disability (Sterling et al., 2003a). Recent evidence suggests that the clinical identiﬁcation of central hyperexcitability is important. This is for two reasons, ﬁrstly some of the sensory features, particularly cold hyperalgesia and intolerance are predictive of poor functional recovery (Kasch et al., 2005; Sterling et al., 2005) and secondly the combined presence of mechanical and cold hyperalgesia in chronic whiplash moderates the effects of physiotherapy treatment (Jull et al., 2007b). In this study a 10-week physiotherapy programme of assurance, advice, speciﬁc exercise and manual therapy, was not effective in decreasing pain and disability in people with chronic whiplash and mechanical and cold hyperalgesia. The same treatment approach in the patients without this sensory presentation led to clinically signiﬁcant reductions in pain and disability (Jull et al., 2007b).

3. The heterogeneity of whiplash—the psychological presentation The psychological presentation of whiplash can be as equally diverse as the physical presentation. There is no doubt that persistent whiplash pain is associated with psychological distress including affective disturbances, anxiety, depression and behavioural abnormalities such as fear of movement (Peebles et al., 2001; Wenzel et al., 2002; Nederhand et al., 2004). Psychological distress is also present in the acute post-injury stage with most people showing some distress regardless of symptom levels (Sterling et al., 2003c). Persistent psychological distress is likely associated with ongoing or non-resolved pain and disability. A recent large cross-sectional study showed an association between anxiety, depression and pain and disability in people whose accidents occurred over two years previously, but not in those with acute injury, suggesting that symptom persistence is the trigger for psychological distress (Wenzel et al., 2002). Longitudinal data indicate that initially elevated levels of distress decrease in those who recover, closely paralleling decreasing levels of pain and disability (Sterling et al., 2003c).

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It is emerging that unique psychological factors may be involved in the aetiology and development of chronic whiplash pain (Sterling et al., 2003c). The role of fear of movement beliefs seems to be a less important factor in whiplash (Sterling et al., 2005) than in low back pain (Vlaeyen and Linton, 2000). The role of coping styles or strategies in whiplash is unclear. Some data indicate that a palliative reaction (e.g. seeking palliative relief of symptoms such as distraction, smoking or drinking) was associated with longer symptom duration (Buitenhuis et al., 2003; Carroll et al., 2006). In contrast Kivioja et al. (2005) found no evidence that different coping styles in the early stage of injury inﬂuenced the outcome at 1-year post accident. The different cohort inception times of these studies may account for the differences in ﬁndings indicating that coping strategies may vary depending on the stage of the condition and this requires further investigation. Whiplash injury differs from most other musculoskeletal pain syndromes in that it is generally precipitated by a traumatic event, namely a MVC. The effect of the psychological stress surrounding the crash itself as opposed to distress about neck pain complaints may have an inﬂuence on outcome. Posttraumatic stress disorder is a common sequalae of severe injuries following a MVC (Kuch et al., 1994). Yet, it is only recently that evidence has emerged to show that it may also play a role in less severe road accident injuries including whiplash. Posttraumatic stress disorder has been diagnosed in some patients with chronic whiplash associated disorders (WAD) (Freidenberg et al., 2006). In addition a moderate/high acute posttraumatic stress reaction (measured with the Impact of Events Scale—IES) is present in some whiplash injured individuals soon after injury (Drottning et al., 1995; Sterling et al., 2003c). The presence of PTSS has been shown to be associated with more severe whiplash complaints and poor functional recovery (Buitenhuis et al., 2006; Sterling et al., 2003c) and is a stronger predictor of poor outcome than both general psychological distress and fear of movement/ reinjury (Sterling et al., 2005, 2006). For the clinician it may be useful to consider psychological distress following whiplash injury as involving both event (MVC) related distress and distress associated with neck pain that contribute to persistent pain and disability (Fig. 1). PTSS may include intrusive thoughts and/or images of the event (in this case the MVC); avoidance behaviour associated with the event such as driving avoidance or via substance abuse; hyperarousal such as panic attacks, hypervigilance and sleep disturbance (Stam, 2007). Yet it is not clear if any of these symptoms play a speciﬁc or greater role than the others in the development of whiplash pain, disability or related adverse health outcomes. Sterling et al. (2003c) showed that avoidance behaviour may have a stronger inﬂuence

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Fig. 1. Event related distress from the motor vehicle crash (MVC) and injury related distress (neck pain) may both contribute to pain and disability following whiplash injury.

on recovery and Buitenhuis et al. (2006) showed that hyperarousal symptoms in the acute stage were a stronger predictor of symptom persistence. Further investigation is required to determine the relative importance of the substrates of posttraumatic stress as this may provide fruitful direction in terms of speciﬁc psychological approaches to whiplash management.

4. Relationships between physical and psychological factors The biopsychosocial model considers pain and disability as the consequence of multiple factors, with biomedical (physiological/physical) and psychological factors intimately intertwined. However it is not clear what the relative role of each factor may be or how they interact. Anecdotally at least, clinicians would be aware of patients who fail to adequately respond to physical interventions until their psychological distress is addressed. Perhaps the continued distress exerts an inﬂuence on the physical presentation of the patient that is difﬁcult to manage via physical means alone. There is data available to support such clinical observations. A multimodal physiotherapy programme whilst decreasing distress in some patients with chronic whiplash showed minimal beneﬁt in patients with mechanical and cold hyperalgesia and moderate symptoms of posttraumatic stress (Jull et al., 2007c). It is possible that the physical and psychological interactions occurring in such patients are too complex to be addressed by physical treatment alone. The exploration of the relationships between physical and psychological factors could assist in determining the nature and timing of various intervention forms. Models have been recently proposed in an attempt to provide a basis for the complex interrelationships

between physical and psychological aspects of the whiplash and other conditions. It has been suggested that the dysregulation of neurobiological pain processing (central hyperexcitability) is related to the stress response and/or sympathetic activation in the early stages following injury and this interaction may be a critical step in the development of persistent pain (McLean et al., 2005). Stress system dysregulation has also been described in posttraumatic stress disorder (Stam, 2007), a factor that occurs concurrently with central hyperexcitability in some whiplash injured people. Passatore and Roatta (2006) go further and outline an argument in which sympathetic activation that occurs via stress can inﬂuence motor and sensorimotor function in addition to contributing to pain processes. These authors argue that increased sympathetic outﬂow (via stress) leads to excessive vasoconstriction which in turn may impair muscle microcirculation and cause structural muscle changes; muscle fatigue and effects on muscle spindles leading to proprioceptive deterioration (Passatore and Roatta, 2006). Whilst data on blood ﬂow to muscles in WAD are not available, sympathetic vasoconstrictive changes in peripheral skin (Sterling et al., 2005), morphological muscle changes (Elliott et al., 2006) and proprioceptive deﬁcits (Treleaven et al., 2003) are present. The links, if any, between these characteristics of whiplash are not yet known but it poses interesting possibilities of the inﬂuence of psychological factors on the physical manifestations of this condition. In fact, the cooccurrence of these myriad of factors in some (but not all) of the whiplash injured has led to calls to regard the condition as a systemic type illness (Ferrari et al., 2005). Nevertheless, there has been some investigation of relationships between the psychological and physical presentations of WAD. Sterling et al. (2008) demonstrated moderate associations between cold pain thresholds and both psychological distress (GHQ-28) and catastrophisation (Pain Catastrophising Scale). Notably there was no relationship between catastrophisation and the intensity of electrical stimulation required to elicit a ﬂexor withdrawal response in biceps femoris in the same patient group (Sterling et al., 2008) (Fig. 2). The latter test is a measure of spinal cord hyperexcitability requiring no cognitive response from the participant (Banic et al., 2004). These ﬁndings indicate that psychological factors play a role in the sensory presentation of whiplash but do not support the assumption that psychological factors are the only or main factors responsible for central hyperexcitability. In particular, spinal cord hyperexcitability appears not to be affected by the psychological factors that were assessed. The clinical relevance of these ﬁndings suggests that both central hyperexcitability and psychological factors will require consideration in the management of whiplash.

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Fig. 2. The nociceptor withdrawal response. Electrical stimulation (Digitimer DS7A, Hertfordshire, UK) is applied to the sural nerve. The current intensity is increased until reﬂex activity (within 90–150 ms post stimulation) is measured in Biceps Femoris via electromyography.

Fig. 3. Sensory hypersensitivity (cold and mechanical hyperalgesia) within one month of injury was associated with persistent PTSS (posttraumatic stress symptoms) at 6 months postinjury but this relationship was mediated by pain and disability levels (Neck Disability Index—NDI). Impaired vasoconstriction measured within 1 month of injury was associated with persistent PTSS but was not related to NDI scores (Sterling and Kenardy, 2006). (Reprinted from Sterling (2007) with permission.)

Relationships between sensory disturbances and PTSS have also been explored. The early presence of sensory hypersensitivity was associated with persistent (6 months) PTSS but this relationship was mediated by initial pain and disability levels (Sterling and Kenardy, 2006). In contrast, early sympathetic disturbance (impaired peripheral vasoconstriction) was associated with persistent PTSS and showed no relationship with initial pain and disability levels (Fig. 3). Although speculative, this may be an indication of a biological vulnerability that may trigger persistent posttraumatic stress and is an area of debate (Stam, 2007). For clinicians it may indicate that patients with higher initial pain and disability levels and/or evidence of sympathetic disturbance could be at risk of persistent PTSS and this should be considered in their management.

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One of the aims of whiplash management is to improve movement or activity levels and to decrease pain. Indeed, there is strong evidence that the maintenance of activity and exercise are efﬁcacious approaches in both the acute and chronic stages of the condition (Rosenfeld et al., 2003; Stewart et al., 2007). A possible hindrance to patients achieving goals in regard to activity and exercise may be related to their perceived fear of pain and/or movement (George et al., 2004) and this is usually recognized by clinicians. By using unique methodology of ambulatory physiological data collection methods where participants wear (for 1–2 days) a device that collects physiological data in conjunction with electronic pain diaries we have been able to explore these relationships. Preliminary data indicate that high levels of PTSS, in particular avoidance symptoms, were more strongly associated with less daily activity than high fear avoidance beliefs (Sterling and Chadwick, 2008). The avoidance scale reﬂects efforts to avoid thoughts, feelings and situations associated with the MVC rather than neck pain, so it is interesting that it was associated with behavioural withdrawal from physical activity. General activity levels were measured in this study and it is not yet clear if the inﬂuences of stress symptoms will extend to effects on the patient’s execution of prescribed exercises. Nonetheless, these ﬁndings suggest that it will be important for clinicians to identify PTSS not only to institute possible psychological referral, but also to ensure that all potential hindrances to improve movement/activity levels and restore function are considered.

5. Clinical assessment of whiplash It is clear that the whiplash condition involves complexities between physiological and psychological factors. Whilst the presence of high initial levels of pain and/or disability are consistent predictors of poor outcome (Scholten-Peeters et al., 2003), the additional presence of sensory hypersensitivity (particularly cold hyperalgesia) and PTSS have been shown to substantially improve predictive capacity (Sterling et al., 2005). These factors may also indicate non-responsiveness to physical interventions (Jull et al., 2007b). The long-term functional status following whiplash may be established within a few months of injury with little further improvement after this time (Rebbeck et al., 2006; Sterling et al., 2006). This reiterates the important role primary care clinicians play in the early post-injury stage and even towards the prevention of chronicity. Clinical examination of the patient with neck pain including whiplash involves consideration of multiple factors including physical (for example range of movement, muscle control, posture); psychosocial, psychological, occupational and activity related features. In the

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case of the whiplash injured person, it is essential that the presence of any ‘red ﬂag’ condition (WAD grade IV—fracture/dislocation) be ruled out. It is beyond the scope of this paper to cover all aspects of clinical assessment and these are detailed elsewhere (Jull et al., 2007a). Instead focus will be placed on essential factors, predictive of outcome that should be included in the clinical assessment of patients with whiplash. The interview stage of the clinical examination will provide important information on both the potential recovery of the person as well as mechanisms underlying the condition. It will be necessary to gain information of pain and disability levels; indications of central hyperexcitability and PTSS.

An appreciation for the presence of central hyperexcitability can also be gained from the physical examination:

5.1. Pain and disability levels

Use of validated questionnaires. The Neck Disability Index (NDI) (Vernon and Mior, 1991) is the most studied in the whiplash context. A cut-off score of X30/100 has been shown to be predictive of poor outcome and this may be a useful reference point for clinicians (Nederhand et al., 2004; Sterling et al., 2005).

5.2. Central hyperexcitability

Features such as high irritability of the condition (Zusman, 2004) and difﬁculty sleeping due to pain may be indicative of central hyperexcitability. Reports of mechanical and thermal allodynia (e.g. pain when shirt sleeve or bedclothes touch the skin, intolerance of cold) infers augmented central pain processing mechanisms (Jensen and Baron, 2003). Neuropathic pain questionnaires (e.g. S-LANSS; Bennett et al., 2005), whilst not yet frequently used in the assessment of musculoskeletal pain, may provide an indication of central hyperexcitability. Thirty percent of an acute whiplash cohort reported features indicative of neuropathic pain (S-LANSS X12) (Sterling and Pedler, 2007). This group showed higher levels of pain and disability, cold hyperalgesia and heightened bilateral responses with the brachial plexus provocation test (BPPT) (Sterling and Pedler, 2007).

and Marmar, 1997) includes an additional scale of hyperarousal symptoms. There are numerous questionnaires available to measure more general psychological distress such as GHQ-28 and SF-36, although the latter has complex scoring procedures (Stewart, 2007).

Allodynia or hyperalgesia on manual examination. Heightened bilateral responses to the BPPT occur in both chronic whiplash (Sterling et al., 2002c) and are associated with neuropathic symptoms in acute whiplash (Sterling and Pedler, 2007). A bilateral loss of elbow extension X301 and moderate reports of pain when testing is taken to pain threshold only is a clinical guide (Sterling et al., 2002c) (Fig. 4). Pressure pain thresholds can be measured with commercially available pressure algometers. Control and whiplash data are available for comparison (Sterling et al., 2002a, b). Clinical measurement of cold pain thresholds is more difﬁcult. The use of thermorollers which can be set at predetermined temperatures has been suggested (Jensen and Baron, 2003). However use of the SLANSS questionnaire shows associations with cold hyperalgesia (Sterling and Pedler, 2007) and may be a useful surrogate measure.

6. Implications for management The clinical assessment should provide clinicians with information of the presence of risk factors for poor

5.3. Posttraumatic stress symptoms

The Impact of Event Scale (IES) has been the most commonly used screening tool for PTSS in whiplash. A score of above 25/26 is indicative of a moderate posttraumatic stress reaction (Horowitz et al., 1979) (Appendix A). A revised version, the IES-R (Weiss

Fig. 4. Heightened bilateral responses to the Brachial Plexus Provocation Test (BPPT) may provide indication of central hyperexcitability. A bilateral loss of elbow extension X301 and moderate reports of pain when testing is taken to pain threshold only is a clinical guide (Sterling et al., 2002c).

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recovery. Clinicians must then make decisions about what management to institute. A patient may be classiﬁed as being of ‘low risk’ of developing persistent pain if they present with lower levels of pain and disability and with no or few signs of central hyperexcitability or PTSS (Fig. 5). However, such patients may still present with movement dysfunction including movement loss, altered muscle control and kinaesthetic deﬁcits. It would be expected that patients with this ‘less complex’ presentation will respond well to physiotherapy interventions. Such interventions may include advice to remain active; encouragement of movement; exercises to improve motor control and strength as well as retraining of sensori-motor deﬁcits (Jull et al., 2007a). There is evidence to indicate that such a treatment approach is more efﬁcacious in patients with a ‘less complex’ presentation (Jull et al., 2007b); although it should be acknowledged that this trial was conducted in participants with chronic whiplash and similar effects in acute whiplash can only be assumed at this stage. In contrast a ‘more complicated’ presentation involving higher levels of pain and disability, central hyperexcitability and/or PTSS will require a more concerted approach to management (Fig. 5). It would seem logical but it is not yet clear whether modulation of central hyperexcitability is possible and if this will be reﬂected in reduced levels of pain and disability. Curatolo et al. (2006) outline three theoretical approaches to the pharmacological treatment of central hypersensitivity. These include medications directed toward: decreasing peripheral nociceptive input; modulating spinal cord hyperexcitability or acting at a supraspinal level and inﬂuencing descending inhibitory pathways. Trials of pharmacological interventions for whiplash are scarce but this is an area for future research. However regardless of the mode of action, the consistent predictive capacity of moderate/high levels of acute pain (Scholten-Peeters et al., 2003) and surgical data showing that early analgesia reduces the incidence

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of chronic pain (Senturk et al., 2002) suggest that adequate pain relief in the acute stage of whiplash injury will likely be beneﬁcial. This may be achieved pharmacologically and musculoskeletal clinicians will play an important role in liaising with medical practitioners to ensure that adequate pain relief is achieved. Of course other approaches besides pharmacological interventions may also exert an inﬂuence on central hyperexcitability. Cognitive approaches including education in various forms have been shown to be effective in reducing pain and disability in whiplash (Oliveira et al., 2006) as well as inﬂuencing pain cognitions in low back pain (Moseley et al., 2004). Such approaches may also decrease central hyperexcitability via descending supraspinal inﬂuences (Wiech et al., 2005) but this has not yet been speciﬁcally investigated. Theoretically physical interventions such as manual therapy, TENS and acupuncture may also be useful in modulating central hyperexcitability as evidence indicates a role of these modalities to activate descending pain inhibitory mechanisms (Skyba et al., 2003; Kong et al., 2005; Sluka et al., 2006) but these interventions also have not been speciﬁcally investigated in WAD. The presence of PTSS must also be considered by the primary care clinician and screening can be performed in this environment. It should be noted that a moderate or higher reaction scored via the IES is not grounds for a diagnosis of posttraumatic stress disorder to be made. This can only be achieved via comprehensive assessment including clinical interview by a qualiﬁed mental health professional (Wilson and Keane, 1997). The decision of when to refer for further assessment and possible intervention should be considered in the context of time since the MVC. Longitudinal data have shown that clinical levels of acute posttraumatic stress were present at 3–4 weeks in approximately 25% of the cohort studied but persisted to 6 months in 13% of the cohort (Sterling and Kenardy, 2006). The timing of psychological referral for an acute posttraumatic stress reaction

Fig. 5. Whiplash associated disorders (WAD) are heterogeneous.

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with physical interventions is hindered. The ﬁndings of these two clinical trials provide evidence that complex and inter-relating mechanisms underlie the whiplash condition and that co-operative inter-professional management will be necessary in those with a ‘more complicated’ presentation.

is controversial with some believing that a too early referral could interfere with normal recovery. The general consensus indicates that an early reaction should be allowed some time for natural recovery to occur. When this recovery is not apparent within 3–4 weeks, guidelines suggest that psychological referral should be instigated (MAA, 2007). For musculoskeletal clinicians this may mean that symptoms indicative of posttraumatic stress should be monitored in the early post-injury period. Additionally sound advice and assurance from musculoskeletal clinicians in this important early postinjury phase may assist in decreasing stress symptoms but this is yet to be tested in an experimental context. This does not imply that physical therapy treatments should be abandoned in patients referred for psychological assessment. Whilst it has been shown that physiotherapy treatment alone failed to improve symptoms of posttraumatic stress in patients with chronic WAD (Jull et al., 2007c), psychological treatment alone has likewise been shown not to have an inﬂuence on pain levels (Blanchard et al., 2003). Furthermore as outlined, the presence of PTSS may inﬂuence the physical presentation of the patient such that progress

7. Summary This paper has discussed the heterogeneity of whiplash with particular regards to physical and psychological characteristics and relationships between them. The heterogeneity dictates that the early assessment (that is in the acute injury stage) of whiplash injured people should attempt to consider features of the condition that are associated with poor recovery. The identiﬁcation of such features in primary care will allow for more speciﬁc treatment directions that may need to include an early co-ordinated inter-professional management approach, particularly in patients with a complex clinical presentation involving central hyperexcitability and symptoms of posttraumatic stress.

Appendix A. Impact of events scale (Horowitz et al., 1979) On ___________________________ you experienced a motor vehicle accident. Below is a list of comments made by people after stressful life events. Please check each item, indicating how frequently these comments were true for you DURING THE PAST SEVEN DAYS. If they did not, occur during that time please mark the ‘NOT AT ALL’ column. 1. I thought about it when I didn’t mean to 2. I avoided letting myself get upset when I thought about it or was reminded of it 3. I tried to remove it from memory 4. I had trouble falling asleep or staying asleep because pictures or thoughts about it came into my mind 5. I had waves of strong feelings about it 6. I had dreams about it 7. I stayed away from reminders about it 8. I felt as if it hadn’t happened or it wasn’t real 9. I tried not to talk about it 10. Pictures about it popped into my mind 11. Other things kept making me think about it 12. I was aware that I still had a lot of feelings about it but I didn’t deal with them 13. I tried not to think about it 14. Any reminder brought back feelings about it 15. My feelings were kind of numb

Not at all Not at all

Rarely Rarely

Sometimes Sometimes

Often Often

Not at all Not at all

Rarely Rarely

Sometimes Sometimes

Often Often

Not Not Not Not Not Not Not Not

all all all all all all all all

Rarely Rarely Rarely Rarely Rarely Rarely Rarely Rarely

Sometimes Sometimes Sometimes Sometimes Sometimes Sometimes Sometimes Sometimes

Often Often Often Often Often Often Often Often

Not at all Not at all Not at all

Rarely Rarely Rarely

Sometimes Sometimes Sometimes

Often Often Often

at at at at at at at at

Scoring: Not at all ¼ 0; Rarely ¼ 1; Sometimes ¼ 3; Often ¼ 5; Total ¼ total the scores. Intrusive subscale: sum of items 1, 4, 5, 6, 10, 11 and 14. Avoidance subscale: sum of items 2, 3, 7, 8, 9, 12, 13 and 15. Total score: 9–25 (mild range); 26–43 (moderate range); 443 (severe range).

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Review

A review of plantar heel pain of neural origin: Differential diagnosis and management Ali M. Alshami, Tina Souvlis, Michel W. Coppieters Division of Physiotherapy, School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, Qld. 4072, Australia Received 18 January 2006; received in revised form 28 December 2006; accepted 15 January 2007

Abstract Plantar heel pain is a symptom commonly encountered by clinicians. Several conditions such as plantar fasciitis, calcaneal fracture, rupture of the plantar fascia and atrophy of the heel fat pad may lead to plantar heel pain. Injury to the tibial nerve and its branches in the tarsal tunnel and in the foot is also a common cause. Entrapment of these nerves may play a role in both the early phases of plantar heel pain and recalcitrant cases. Although the contribution of nerve entrapment to plantar heel pain has been well documented in the literature, its pathophysiology, diagnosis and management are still controversial. Therefore, the purpose of this article was to critically review the available literature on plantar heel pain of neural origin. Possible sites of nerve entrapment, effectiveness of diagnostic clinical tests and electrodiagnostic tests, differential diagnoses for plantar heel pain, and conservative and surgical treatment will be discussed. r 2007 Elsevier Ltd. All rights reserved. Keywords: Subcalcaneal pain; Plantar fasciitis; Nerve entrapment; Neurodynamics

1. Introduction Plantar heel pain is a common condition (Hurwitz, 1997; Juliano and Harris, 2004). It occurs in approximately 15% of all adults with foot problems (McCarthy and Gorecki, 1979). Several well-known conditions may lead to plantar heel pain such as plantar fasciitis, calcaneal fracture, rupture of the plantar fascia and atrophy of the heel fat pad (Schon et al., 1993). Plantar heel pain may also have a neural origin, with a lesion or dysfunction of the tibial, plantar or calcaneal nerves (Johnson et al., 1992; Goolsby, 2003). Nerve entrapment may play a role in both acute and chronic conditions of plantar heel pain (Kenzora, 1987; Oztuna et al., 2002). The ﬁrst reference to plantar heel pain of neural origin was published in a Dutch language article by Roegholt in 1940. Based on dissection studies, Roegholt postulated that plantar heel pain could be due to entrapment Corresponding author. Tel.: +61 7 3346 7468; fax: +61 7 3365 1622. E-mail address: [email protected] (A.M. Alshami).

1356-689X/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2007.01.014

of the inferior calcaneal nerve (cited in Rondhuis and Huson, 1986). However, nerve entrapment as a cause of plantar heel pain was neglected during the following two decades. In 1960, Kopell and Thompson (1960) hypothesised that trauma to the calcaneal nerves could cause plantar heel pain. To date, although nerve entrapment in plantar heel pain is well documented (e.g. Baxter and Pfeffer, 1992; Oztuna et al., 2002), its pathophysiology, diagnosis and management are still subject to debate. The aim of this article was to critically review the literature on plantar heel pain of neural origin. We will discuss possible sites of nerve entrapment, the clinical presentation, differential diagnoses, and conservative and surgical treatment.

2. Search strategy Peer-reviewed journal articles that predominantly focused on plantar heel pain of neural origin or that

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discussed relevant biomechanics of the tibial, plantar and calcaneal nerves were included in this review. NonEnglish language reports were excluded. Studies were identiﬁed using the following databases: Ovid Medline (from 1966 to 07/2006), Web of Science (from 1900 to 07/2006), PubMed (from 1930 to 07/2006), PEDro (07/2006), EMBASE (from 1900 to 07/2006), Cochrane Database of Systematic Reviews (1800 to 07/2006), Cochrane Central Register of Controlled Trials (from 1800 to 07/2006), CINAHL (from 1982 to 07/2006) and AMED (from 1985 to 07/2006). The keywords ‘heel pain’, ‘painful heel’, ‘plantar fasciitis’, ‘heel spur’ and ‘foot pain’ were combined with each of the following search terms: ‘nerve’, ‘entrapment’, ‘compression’, ‘tibial’, ‘plantar’ and ‘calcaneal’. Reference lists of located articles were also searched. This search strategy identiﬁed 69 journal articles. Of these, 57 were primary articles (Table 1) while the remaining 12 were review papers (Table 2). Tables are only published in the online version of this article.

PF MPN LPN

FR

3. Nerve entrapment sites The tibial nerve is the larger of the two major divisions of the sciatic nerve, and distally it divides into the following branches: medial calcaneal nerve (MCN), medial plantar nerve (MPN), lateral plantar nerve (LPN) (Gray et al., 2005) and the ﬁrst branch of the LPN (Przylucki and Jones, 1981) (Fig. 1). While contribution of the MCN to plantar heel pain of neural origin is well documented (Savastano, 1985; Beito et al., 1989), most authors have implicated the ﬁrst branch of the LPN in this condition (Baxter and Pfeffer, 1992; Watson et al., 2002). Patients with entrapment of the ﬁrst branch of the LPN represent 15–20% of the patients with chronic plantar heel pain (Baxter et al., 1989; Pfeffer, 2001). Compression of the tibial nerve at the tarsal tunnel, a condition called tarsal tunnel syndrome (TTS), can also contribute to plantar heel pain (Kinoshita et al., 2001; Lau and Stavrou, 2004). Entrapment of the MPN occurs where the fascial sling can bind the nerve beneath the talus and navicular bone (Schon, 1994; McCluskey and Webb, 1999). We will discuss entrapment of these nerves in detail below. 3.1. Entrapment of the LPN and its first branch The LPN supplies most of the foot muscles and the skin of the lateral one-third of the plantar aspect of the foot and the fourth and ﬁfth toes (Gray et al., 2005) (Fig. 2). Entrapment of the LPN can result from compression between the abductor hallucis and quadratus plantae muscles (Peri, 1991; May et al., 2002). The ﬁrst branch of the LPN, also called the nerve to abductor digiti minimi (Przylucki and Jones, 1981),

TN

1st B-LPN MCN Fig. 1. Medial view of right foot demonstrating the relation of the nerves to other structures. 1st B-LPN, ﬁrst branch of lateral plantar nerve (LPN); FR, ﬂexor retinaculum; MCN, medial calcaneal nerve; MPN, medial plantar nerve; PF, plantar fascia; TN, tibial nerve.

innervates the ﬂexor digitorum brevis, quadratus plantae and abductor digiti minimi muscles (Przylucki and Jones, 1981; Louisia and Masquelet, 1999). Although it gives off sensory branches to the calcaneal periosteum (Arenson et al., 1980; Rondhuis and Huson, 1986), this nerve does not supply the skin (Park and Del Toro, 1996; Dellon, 2001). Variations in the origin of the ﬁrst branch of the LPN have been reported. The branch may either originate rather distally from the LPN (Gray et al., 2005) or relatively proximally (0.5 cm (Arenson et al., 1980) to 1.7 cm (Louisia and Masquelet, 1999) distal to the medial calcaneal tuberosity) (Fig. 3). The close proximity of this nerve to the calcaneal tuberosity suggests the possibility of an entrapment, resulting in plantar heel pain (Przylucki and Jones, 1981; Louisia and Masquelet, 1999). The majority of studies included in this review reported that entrapment of the ﬁrst branch of the LPN is the most common cause of plantar heel pain of neural origin (Table 1, electronic version only). Entrapment of this nerve can occur at different sites: (1) where the nerve passes at the sharp edge of the deep fascia of the abductor hallucis and (2) just distal to the medial

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LPN 1st B-LPN

Fig. 3. Variations in the distribution of the ﬁrst branch of lateral plantar nerve (1st B-LPN). (A) The nerve originates more distally from the LPN as described in Gray’s anatomy. (B) The nerve branches off more proximally as shown in cadaver studies. Adapted from Przylucki and Jones (1981) and original reproduced by kind permission of The American Podiatric Medical Association.

TIbia

Fig. 2. Cutaneous innervation of the sole of right foot. LPN, lateral plantar nerve; MCN, medial calcaneal nerve; MPN, medial plantar nerve; SN, saphenous nerve.

TN

Fib Talus

edge of the calcaneus (Baxter and Thigpen, 1984), particularly in the presence of a calcaneal spur or plantar fasciitis (Przylucki and Jones, 1981; Louisia and Masquelet, 1999). While Rondhuis and Huson (1986) did not observe the ﬁrst site in either 4 foetal or 34 adult dissected feet, they reported a site of possible entrapment between the abductor hallucis and the medial head of quadratus plantae muscle (Fig. 4). Histological examination of this nerve revealed hypertrophy of the perineural connective tissues (Przylucki and Jones, 1981), loss of large myelinated ﬁbres and an increase in endoneural collagen, suggesting chronic compression (Baxter and Pfeffer, 1992).

QP

Entrapment Site

1st B-LPN MCN AH

Calcaneus ADM FDB PF

3.2. Entrapment of the MCN

Fig. 4. Cross-sectional view of right ankle and foot. Note the possible entrapment site of the ﬁrst branch of lateral plantar nerve (1st B-LPN) between the deep fascia of the abductor hallucis (AH) muscle and the medial head of quadratus plantae (QP) muscle. ADM, abductor digiti minimi; Fib, ﬁbula; FDB, ﬂexor digitorum brevis; MCN, medial calcaneal nerve; PF, plantar fascia; TN, tibial nerve. Adapted from Baxter and Pfeffer (1992) and original reproduced by kind permission of Lippincott Williams and Wilkins.

The MCN usually divides into anterior and posterior branches (Henricson and Westlin, 1984; Louisia and Masquelet, 1999). It provides sensory innervation to most of the heel fat pad and to the superﬁcial tissues overlying the inferior part of the calcaneus (Louisia and Masquelet, 1999) (Fig. 2).

MCN is the second most commonly reported nerve that has been related to plantar heel pain of neural origin (Table 1, electronic version only). In a case report, Shacklock (1995) concluded that plantar heel pain and paraesthesiae in a patient with diabetes resulted from a

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neuropathy of the MCN and tibial nerve. However, entrapment of the MCN may not be a very prevalent condition as only 5 out of 200 surgical cases were consistent with MCN entrapment (Schon et al., 1993). Most branches of the MCN lie superﬁcially to the abductor hallucis, ﬂexor digitorum brevis and plantar fascia (Arenson et al., 1980; Louisia and Masquelet, 1999). The nerves are less likely to be compressed within these structures, but can be irritated and traumatised following atrophy of the heel fat pad (Kopell and Thompson, 1960; Davidson and Copoloff, 1990). 3.3. Entrapment of the MPN The MPN innervates the abductor hallucis, ﬂexor hallucis brevis, ﬂexor digitorum brevis and ﬁrst lumbrical, and the skin of the medial two-thirds of the plantar aspect of the foot (Gray et al., 2005) (Fig. 2). Entrapment of the MPN is not as common as entrapment of the other nerves (Murphy and Baxter, 1985), particularly as an isolated entity (Raikin and Schon, 2000). Out of 21 cases diagnosed with nerve entrapment in the ankle and foot, Murphy and Baxter (1985) concluded that only one case was consistent with MPN entrapment.

4. Clinical presentation The diagnosis of plantar heel pain of neural origin is based on a comprehensive history and physical examination (Baxter and Pfeffer, 1992; Jolly et al., 2005). 4.1. Pain In patients with plantar heel pain of neural origin, pain is usually characterised as burning, sharp, shooting, shock-like, electric, localised or radiating either proximally or distally (Schon et al., 1993; Goecker and Banks, 2000), and occasionally as dull aching (Fredericson et al., 2001; May et al., 2002). Typically, pain is worse during or after weight-bearing activities and improves with rest (Pfeffer, 1995; May et al., 2002). However, pain may also occur with rest and in nonweight bearing positions (Hendrix et al., 1998; Barrett and O’Malley, 1999). Pain at night may be due to nerve compression as a result of venostasis (slowing of venous outﬂow) and venous engorgement (local congestion and distension with blood) (Kopell and Thompson, 1960; Doxey, 1987). 4.2. Post-static dyskinesia A common ﬁnding in patients with plantar heel pain of neural origin is pain when a patient ﬁrst stands after periods of rest, a phenomenon called post-static

dyskinesia (Oztuna et al., 2002; Jolly et al., 2005). Severe pain in the morning after rising from bed was found in a large number of patients with plantar heel pain of neural origin (Schon et al., 1993; Oztuna et al., 2002). Post-static dyskinesia is thought to be caused by ﬂuid accumulation around the nerve during rest (Davidson and Copoloff, 1990). Upon taking the ﬁrst steps, this ﬂuid presses against the nerve, causing pain, and ‘‘as the ﬂuid is milked out of the nerve sheath some of the pain subsides’’. The ﬂuid then builds up as the day progresses and symptoms may return (Davidson and Copoloff, 1990). Jolly et al. (2005) hypothesised that muscular activity associated with ambulation reduces venous pooling and intra-compartmental pressures. Therefore, pain of neural origin may decrease with sustained ambulation, whereas pain in plantar fasciitis is likely to increase (Jolly et al., 2005). It should be noted, however, that post-static dyskinesia is not pathognomonic for plantar heel pain of neural origin. It also occurs frequently in patients with plantar fasciitis. 4.3. Paraesthesiae and neurological changes Although sensory deﬁcit is not common in entrapment of the ﬁrst branch of the LPN (Pfeffer and Baxter, 1991), patients with TTS often complain of sensory disturbances (Schon and Baxter, 1990; Schepsis et al., 1991), such as tingling and/or numbness around the medial and plantar aspects of the heel (Baxter, 1994; May et al., 2002). Kinoshita et al. (2001) found that 35 out of 44 feet with TTS had diminished sensation in the distribution of the MPN, 7 had diminished sensation in the distribution of both MPN and LPN, and 2 had diminished sensation in the distribution of both MPN and MCN.

5. Diagnostic tests 5.1. Clinical tests 5.1.1. Palpation Palpation over the abductor hallucis and/or on the medial calcaneal tuberosity reproduced symptoms in all patients (33) with suspected neurological plantar heel pain (Schon et al., 1993). The diagnosis of entrapment of the ﬁrst branch of the LPN should not be made without the presence of maximal tenderness over the nerve, although the entire heel and the proximal plantar fascia may also be tender (Baxter and Pfeffer, 1992; Goecker and Banks, 2000) (Fig. 5). Diagnosis of entrapment of the anterior branch of the MCN can be substantiated by the following palpatory ﬁndings: (1) maximal tenderness over the medial anterior part of the heel fat pad and abductor hallucis, (2) distally radiating pain with

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Cadaver studies showed a signiﬁcant increase in tension in the tibial nerve and LPN within the tarsal tunnel during dorsiﬂexion, eversion and combined DF/ Eve (Daniels et al., 1998; Lau and Daniels, 1998). Metatarsophalangeal extension further increases strain in the MPN and tibial nerve (Alshami et al., 2007). Unfortunately, metatarsophalangeal extension also increases strain in the plantar fascia (Alshami et al., 2007), which may compromise the usefulness of the DF/Eve test in the differential diagnosis of plantar heel pain. In order to differentiate between structures, neurodynamic tests have been suggested for plantar heel pain (Butler, 2000, p. 414; Shacklock, 2005, pp. 232–235). These tests are sequences of movements aimed to ‘‘test the mechanics and physiology of a part of the nervous system’’ (Butler, 2000, p. 98). In a case study, Meyer et al. (2002) could reproduce plantar heel pain of neural origin with hip ﬂexion when added to DF/Eve (a modiﬁed straight leg-raising test). In a biomechanical study, Coppieters et al. (2006) demonstrated that adding hip ﬂexion to ankle dorsiﬂexion with the knee in extension increased strain in the tibial and plantar nerves at the ankle and foot, without increasing tension in the plantar fascia. Although clinical studies are needed, this suggests that the modiﬁed straight legraising test may be a valuable tool to differentiate plantar heel pain of neural origin from other common conditions, such as plantar fasciitis.

Fig. 5. Sole of right foot with areas of maximal tenderness for different conditions associated with plantar heel pain: (1) plantar fasciitis (or heel pain syndrome according to Spiegl and Johnson (1984); Kenzora (1987) and Pfeffer and Baxter (1991)), (2) entrapment of the ﬁrst branch of lateral plantar nerve, (3) true/isolated plantar fasciitis according to Pfeffer and Baxter (1991) and Karr (1994) and (4) fat pad atrophy. Adapted from Baxter and Pfeffer (1992) and original reproduced by kind permission of Lippincott Williams and Wilkins.

pressure on the nerve and (3) only minimal tenderness over the plantar fascia origin (Henricson and Westlin, 1984). With MPN entrapment, tenderness is typically located over the plantar aspect of the medial arch around the navicular tuberosity (Schon and Baxter, 1990). 5.1.2. Dorsiflexion-eversion and neurodynamic tests Kinoshita et al. (2001) devised the dorsiﬂexion-eversion (DF/Eve) test for TTS. With this test, all metatarsophalangeal joints are passively extended while the ankle is held in dorsiﬂexion and eversion. This test reproduced or aggravated the symptoms in the majority of patients with TTS (36 out of 44 feet), but not in a healthy control group (Kinoshita et al., 2001).

5.1.3. Plantar flexion-inversion test Passive plantar ﬂexion-inversion may reproduce or aggravate symptoms as the test increases pressure on the tibial nerve in the tarsal tunnel (Trepman et al., 1999). During surgery, Hendrix et al. (1998) observed that this manoeuvre reduced the width of the tarsal canal and compressed the LPN, and the ﬁrst branch of the LPN and MPN. 5.1.4. Tinel’s test Tinel’s test consists of tapping along the course of a nerve. The test is considered positive when it results in tingling along the nerve distribution. While Tinel’s test is often positive in TTS (Schon and Baxter, 1990; Kinoshita et al., 2001), and can be positive in MPN entrapment (Schon and Baxter, 1990), the test is usually negative in entrapment of the ﬁrst branch of the LPN (Fredericson et al., 2001). Baxter and Pfeffer (1992) found a positive Tinel’s test in only 12 of 69 heels (17%) with entrapment of the ﬁrst branch of the LPN. 5.2. Electrodiagnostic tests 5.2.1. Electromyography and nerve conduction studies Electromyography and nerve conduction studies have revealed abnormalities in the MPN (Schon et al., 1993) and LPN (Johnson et al., 1992; Schon et al., 1993).

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However, their role in the diagnosis of nerve involvement in plantar heel pain is controversial. Schon et al. (1993) reported that electrodiagnostic tests are only an adjunct and are not a substitute for clinical examination. In general, up to 50% of electrophysiological studies can return false-negative results for large nerve compression neuropathies (Dellon, 1999) and they are even less accurate for smaller nerve ﬁbres (Magda et al., 2002). 5.2.2. Quantitative sensory testing Quantitative sensory testing (QST) aims to determine pain mechanisms by assessing the function of both large and small sensory nerve ﬁbres (Magda et al., 2002; Siao and Cros, 2003). QST devices generate vibratory, thermal and painful stimuli as well as electrical impulses (Shy et al., 2003). Although it should not be the only tool to diagnose neurological disorders, Shy et al. (2003) concluded that QST is potentially a useful method to measure sensory impairment. Only a few studies have used some modalities of QST to investigate sensory dysfunctions in patients with plantar heel pain (Tassler and Dellon, 1996; Rose et al., 2003). Tassler and Dellon (1996) demonstrated higher cutaneous pressure thresholds in 22 patients with TTS compared to age-matched controls. Rose et al. (2003) found higher pressure thresholds in the cutaneous distribution of the MCN in 59 of 82 patients (72.2%) with plantar heel pain compared with normative, agerelated pressure thresholds. Because they found abnormalities in the cutaneous distribution of both the MCN and MPN in 49.5% of the patients, Rose et al. (2003) concluded that a more proximal disorder, such as lumbosacral nerve root compression, should also be considered. 5.3. High-resolution ultrasound Ultrasound imaging can be used to detect nerve pathology. However, the majority of studies have focused on the median nerve at the carpal tunnel. Nerve swelling (Wong et al., 2002; Yesildag et al., 2004) and diminished lateral movement of the median nerve (Greening et al., 2001) have been demonstrated. Although ultrasound has been suggested for differential diagnosis of TTS (Peer et al., 2003), studies are not yet available.

the above-mentioned signs strongly support a neurogenic cause of plantar heel pain, whereas the presence of only one sign should not be considered until other causes such as plantar fasciitis have been excluded. Although further validation is required, we believe that QST and neurodynamic tests such as the modiﬁed straight leg-raising test may also have a role in the diagnosis of plantar heel pain of neural origin. Among others, the following differential diagnoses should be ruled out. 6.1. Plantar fasciitis Plantar fasciitis is the most common cause of plantar heel pain (Aldridge, 2004) and the term has been used generically to describe heel pain at the origin of the plantar fascia on the medial calcaneal tuberosity (Lemont et al., 2003). Chronic plantar fasciitis is predominantly characterised by a marked collagen degeneration of the plantar fascia and inﬂammation has been rarely reported (Wearing et al., 2006). The typical presentation is pain that is worse when standing after periods of rest or on taking the ﬁrst steps in the morning (post-static dyskinesia) (Aldridge, 2004). Maximal tenderness is located over the origin of the plantar fascia and along the fascia 1–2 cm distal to the origin (Henricson and Westlin, 1984; Pfeffer and Baxter, 1991) (Fig. 5). As it is difﬁcult to differentiate between pain from the origin of the plantar fascia and bony sources of heel pain at the medial calcaneal tuberosity, such as calcaneal periostitis, some authors advocate the term ‘heel pain syndrome’ to refer to pain over the medial calcaneal tuberosity (Spiegl and Johnson, 1984; Kenzora, 1987; Pfeffer and Baxter, 1991). Pfeffer and Baxter (1991) and Karr (1994) reserve the term ‘true/isolated plantar fasciitis’ to a disorder that affects the middle portion of the plantar fascia. 6.2. Fat pad atrophy In patients with a soft and thin heel fat pad, pain is usually aggravated by hard-soled shoes and walking on hard surfaces. Pain is most intense over the central portion of the heel fat pad (Fig. 5). The pain does not radiate, and the medial calcaneal tuberosity and plantar fascia are not tender (Pfeffer and Baxter, 1991; Baxter and Pfeffer, 1992).

6. Differential diagnoses 6.3. Tumours Hendrix et al. (1998) found that all of their 51 patients with chronic plantar heel pain due to nerve entrapment demonstrated (1) loss of plantar sensation, (2) a positive plantar ﬂexion-inversion test, (3) a positive Tinel’s test and (4) pain and paraesthesia on nerve compression. Jolly et al. (2005) suggested that the presence of all of

Although uncommon, benign tumours or neuromas of the ﬁrst branch of the LPN (Shandles et al., 2002; Marui et al., 2004), MCN (Davidson, 1977) and MPN (Marui et al., 2004) have been related to plantar heel pain. Patients with neuroma of the MCN may complain

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of occasional local paraesthesia and loss of sensation (Davidson et al., 1977), and a Tinel’s test may also be positive (Davidson and Copoloff, 1990). 6.4. Proximal nerve lesions Neurological examination should be performed to exclude proximal nerve disorders (Jolly et al., 2005). Schon et al. (1993) found that 2 patients out of 23 with plantar heel pain had electrophysiological evidence of S1 radiculopathy. The tibial nerve in the popliteal fossa can be compressed by the tendinous arch of the soleus muscle (Mastaglia, 2000) or by a Baker’s cyst (Willis and Carter, 1998), which can radiate pain to the heel. Other differential diagnoses such as rupture of the plantar fascia, bone fractures, bursitis, tendonitis, arthritis, osteomyelitis and bone cysts (Brown, 1996; Aldridge, 2004) should also be considered.

7. Treatment Surprisingly, according to the literature, the current treatment of plantar heel pain due to nerve entrapment is similar to other types of plantar heel pain (Baxter et al., 1989; Johnston, 1994). The fact that the conservative management of plantar heel pain is still challenging (Watson et al., 2002) can be attributed to the difﬁculties in establishing the correct differential diagnosis and aetiology. 7.1. Conservative treatment In general, conservative treatment of plantar heel pain may include rest, non-steroidal anti-inﬂammatory drugs, corticosteroid injections, extracorporeal shock wave therapy, laser, local anaesthetic injections, heel pads and heel cups, night splints, medial longitudinal arch supports, strapping, foot orthoses, soft-soled shoes, stretching exercises for the Achilles tendon and plantar fascia, ultrasound and casting (e.g. Pfeffer, 1995; Crawford and Thomson, 2003). In a systematic review, Crawford and Thomson (2003) concluded that the effectiveness of the treatment modalities for plantar heel pain have not been established in randomised controlled trials. They found limited evidence for the effectiveness of local corticosteroid therapy for shortterm pain relief, usually around 4 weeks. However, complications such as plantar fascia rupture can result from corticosteroid injections (Sellman, 1994; Acevedo and Beskin, 1998). There is a limited number of case studies that have applied nerve mobilisation techniques in the treatment of patients with plantar heel pain of neural origin (Shacklock, 1995; Meyer et al., 2002). Shacklock (1995) used knee extension movements in supine position in a

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patient with a neuropathy of the MCN and tibial nerve at the tarsal tunnel. Meyer et al. (2002) performed knee extension movements in a slump position in a patient with a possible entrapment of the MCN and tibial nerve at the ankle and/or at the arch of the soleus muscle. Both case studies reported positive outcomes with no adverse effects. 7.2. Surgical interventions Approximately half of the identiﬁed primary articles were surgical studies (Table 1, electronic version only). Surgery is considered if at least 6–12 months of conservative treatment has failed (Karr, 1994; Watson et al., 2002). Surgical decompression of the ﬁrst branch of the LPN (Baxter and Pfeffer, 1992; Sammarco and Helfrey, 1996; Conﬂitti and Tarquinio, 2004), MCN (Davidson, 1977; Bordelon, 1983; Savastano, 1985), LPN and MPN (Hendrix et al., 1998) relieved symptoms in patients with plantar heel pain. Bordelon (1983) and Watson et al. (2002) suggested that a combination of surgical procedures may be needed only if a speciﬁc diagnosis cannot be made. Nevertheless, for the majority of the reviewed primary studies it is difﬁcult to establish the effect of a speciﬁc surgical intervention as often several surgical procedures were performed simultaneously and control interventions were not considered. Postoperatively, different protocols have been brieﬂy discussed in the literature. Generally, the use of special postoperative shoes or walking casts has been recommended for a period of 1–4 weeks. After cast removal, weight bearing is resumed as tolerated and active range of motion exercises are encouraged (Beito et al., 1989; Hendrix et al., 1998; Watson et al., 2002).

8. Conclusion and recommendations Through the decades, attention has shifted away from considering inﬂammation of the plantar fascia as the principal source of plantar heel pain. Recently, nerve entrapment has also been considered an important cause of plantar heel pain. In particular, the ﬁrst branch of the LPN and the MCN are implicated in this condition. The diagnosis of plantar heel pain with a neural origin is dependent on a careful history and physical examination. Evidence for the role of QST in the diagnosis is emerging. The authors believe that the current inconsistency in the literature regarding the diagnosis and management of plantar heel pain with a neural origin can be explained by (1) difﬁculty in establishing the correct cause of plantar heel pain, (2) lack of prospective-controlled studies, (3) different characteristics of subjects and different methodologies used in the studies, (4) complexity of foot anatomy and biomechanics and

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(5) complexity of neuropathic pain in terms of its pathophysiology, diagnosis and treatment. Based on the available literature, there is lack of evidence on treatment approaches although the majority of patients with plantar heel pain improve with conservative treatment. Further studies are needed to investigate the mechanisms of pain in patients with plantar heel pain and to establish the role of QST and neurodynamic tests such as modiﬁed straight leg-raising in differential diagnosis of neurological plantar heel pain. Studies that investigate the beneﬁts of adding speciﬁc nerve gliding exercises to the conservative and postoperative management of plantar heel pain of neural origin are also required.

Acknowledgements The authors would like to thank Professor Tom McPoil for his valuable comments on a previous version of this paper.

Appendix A. Supporting Information Supplementary data associated with this article can be found in the online version at doi:10.1016/j.math.2007. 01.014.

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Manual Therapy 13 (2008) 112–121 www.elsevier.com/locate/math

Original article

Postpartum characteristics of rectus abdominis on ultrasound imaging Yvonne Coldrona,, Maria J. Stokesb, Di J. Newhamc, Katy Cookd a

Department of Basic Medical Sciences, St George’s, University of London, UK School of Health Professions and Rehabilitation Sciences, University of Southampton, UK c Division of Applied Biomedical Research, School of Biomedical & Health Sciences, King’s College London, UK d Fetal Medicine Unit, St. George’s Hospital NHS Trust, London, UK b

Received 7 November 2005; received in revised form 22 August 2006; accepted 20 October 2006

Abstract This cross-sectional and partial longitudinal study aimed to characterize changes in rectus abdominis (RA) and provide reference ranges for the ﬁrst year postpartum. Ultrasound scanning was used at four stages postnatally to measure cross-sectional area (CSA), thickness, width (indirectly using a shape value) and inter-recti distance (IRD). One hundred and ﬁfteen postnatal women (though some postnatal subjects appeared in more than one postnatal group thus giving a total of 183 data points) and 69 age-matched nulliparous female controls were recruited. Postnatal subjects were studied at Day 1 (PN1; n ¼ 63) and at 2 (PN2; n ¼ 55), 6 (PN3; n ¼ 39) and 12 (PN4; n ¼ 26) months postpartum. Longitudinal data were analysed for CSA, thickness, shape (indirect width measurement) (df ¼ 67) and IRD (df ¼ 62). The mean CSA of the PN1 group was signiﬁcantly larger (Po0.001) than in controls and decreased (Po0.0021) by 12 months. In all postnatal groups, RA was signiﬁcantly thinner (Po0.0001, PN1–PN3; Po0.0478, PN4), wider (Po0.0001, PN1–PN3; P ¼ 0.0326, PN4) and the IRD was signiﬁcantly larger (Po0.0001, PN1–PN4) than in controls. Over 2 months postpartum, RA became thicker (P ¼ 0.0003) and the width and IRD decreased (Po0.0001 and P ¼ 0.0002, respectively) but did not return to control values by 12 months. These results have implications for strength of RA postpartum and anterior abdominal wall stiffness, which together with other muscle characteristics could inform development of effective postnatal exercise programmes. r 2006 Elsevier Ltd. All rights reserved. Keywords: Rectus abdominis; Postpartum; Ultrasound scanning; Muscle characteristics

1. Introduction The main musculoskeletal problems encountered in postnatal women are low back and pelvic girdle pain (Mantle et al., 1977; Ostgaard et al., 1991, 1996, 1997; Ostgaard and Andersson 1992; Ostgaard, 1997; Noren et al., 2002), diastasis recti abdominis (DRA) (Bursch, 1987; Boissonnault and Blaschak, 1988; Potter et al., 1997a; Lo et al., 1999; van Uchelen et al., 2001; Nahas Corresponding author. Physiotherapy Department, Mayday Healthcare NHS Trust, London Road, Thornton Heath, Surrey CR7 7YE, UK. Tel.: +442084013093. E-mail address: [email protected] (Y. Coldron).

1356-689X/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2006.10.001

et al., 2005) and poor control of the abdominal muscles (Gilleard and Brown, 1996; Potter et al., 1997b). As well as consulting physiotherapists for clinical problems, postnatal women often attend exercise groups to restore their ﬁgure and ﬁtness. The exercises used in physiotherapy departments or exercise classes are not based on evidence of changes to the abdominal muscles in pregnancy, and very little literature about muscular changes during and after pregnancy is available. One of the muscles thought to undergo change in pregnancy is the rectus abdominis (RA) (Gilleard and Brown, 1996; Lo et al., 1999). The two bellies of RA extend the whole length of the anterior abdomen and are connected by the linea alba.

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The main function of RA is to ﬂex the trunk on a ﬁxed pelvis or ﬂex the pelvis on a ﬁxed trunk (Williams et al., 1989; Kendall et al., 1993). Working isometrically it contributes to trunk stability to allow limb movement (Negrao Filho et al., 1997). The distribution of muscle ﬁbres in a skeletal muscle have been classiﬁed on the basis of their content of different myosin heavy chain (MHC) isoforms and identiﬁcation of three main human muscle ﬁbre types (I, IIA and IIX (previously called IIB)) have been established (Bottinelli et al., 1999). A faster Type II (IIB) MHC isoprotein may also be expressed in skeletal muscle (Graziotti et al., 2001). In a histological study of the abdominal muscles, Caix et al. (1984) reported approximately twice as many Type I as Type II muscle ﬁbres and relatively few Type IIX ﬁbres compared with Type IIA in the RA muscle. However, Haggmark and Thorstensson (1979) found the distribution of the two main ﬁbre types, Types I and II, to be similar (mean 55–58% Type I, 15–23% Type IIA, 21–28% Type IIX ﬁbres) but a large inter-individual variation was found. As the fetus grows, the RA of the mother elongates as her abdominal wall expands. The linea alba softens and the two bellies curve round the abdominal wall with most separation occurring at the umbilicus (Boissonnault and Blaschak, 1988; Fast et al., 1990; Gilleard and Brown, 1996). This gap, the inter-recti distance (IRD), may vary from 2 to 3 cm wide and 2 to 5 cm long to 20 cm wide and involving the whole length of RA (see Polden and Mantle, 1990). This increased IRD is often referred to as a diastasis or divarication of RA (DRA). Imaging techniques using computerized tomography (CT) scans have been used to set a pathological DRA at an IRD of 42.7 cm at the level of the umbilicus (Rath et al., 1996). Using ultrasound imaging, this criterion has been used to measure IRD after abdominoplasty for postpartum DRA and determine those patients who needed further surgery (van Uchelen et al., 2001).

113

Normative data for postpartum RA thickness, width and cross-sectional area (CSA) are not available. Knowledge of changes in RA postpartum is important for the development of rational postnatal exercise programmes and general postnatal advice. This study aimed to characterize the size and shape of RA and the IRD postpartum and also to produce normative data for the resolution of these variables during the ﬁrst postnatal year.

2. Methodology 2.1. Study design A prospective cross-sectional cohort study design was utilized and repeated measures were used (where possible) to provide a partial longitudinal design. 2.2. Subjects A total of 69 nulliparous female controls (CTL) and 115 postnatal women (both primiparous [n ¼ 72] and multiparous [n ¼ 43]) participated in the study. Some postnatal subjects appeared in more than one postnatal group thus giving a total of 183 data points. Control subjects were nulliparous women of childbearing age (mean age 27, range 18–45 years). Postnatal subjects (mean age 32, range 19–46 years) were studied on the ﬁrst day (PN1; n ¼ 63); 8 weeks (PN2; n ¼ 55); 6 months (PN3; n ¼ 39) and 12 months (PN4; n ¼ 26) after delivery. A small proportion of women (45) included in the PN1–4 groups formed the longitudinal part of the study and contributed 67 df to the trend estimation and testing of the average rate of change of RA thickness, shape variable (indirect width measurement) CSA over a 12-month postpartum period (Table 1). Due to problems imaging the IRD/DRA in a

Table 1 Contribution of data points to repeated measures trend estimation No. of data points available

No. of subjects

No. of data points

No. of df

1

70

70

0

2 3

29 9

58 27

29 18

4

7

28

21

115

183

68a

Total

Data points contributing to the trend estimation Single points contributing nothing Pairs contributing 1 df each Triplets contributing 2 df each Quadruplets contributing 3 df each

The numbers of data points used to estimate the common slope (i.e. average rate of change per month) of ultrasound measurements of thickness, shape value (indirect width measurement) and cross-sectional area of the rectus abdominis (RA) muscle are shown. The degrees of freedom (df) are calculated from those subjects who contributed at least two data points. There were 115 subjects in total contributing 68–1 ¼ 67 df to the estimation and testing of the average rate of change. a One more df used to estimate the common slope giving 67 df overall.

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minority of subjects, the IRD was not measured on every subject at every occasion so slightly fewer data points were available for analysis (df ¼ 62). 2.3. Equipment An Aloka SSD ultrasound scanner (Aloka Co. Ltd, Mitaka-shi, Tokyo, Japan), with a 5 MHz linear probe (11 cm footprint) was used. The image was frozen and then downloaded to a computer using a frame grabber and measured off-line with on-screen callipers using UltraSound Image Concatenation and Analysis (USICA) software (developed by the Department of Medical Physics, St. George’s Hospital, London). 2.4. Procedure With the subject in crook lying and knees ﬂexed over two pillows, measurements were taken of resting RA thickness, CSA, shape of RA and the IRD. The bottom edge of the probe was placed centrally on the skin just cephalad to the umbilicus. To determine the IRD the two medial ends of the recti were identiﬁed and two images taken (Fig. 1). The transducer was then moved laterally until the full image of the left RA was seen on the screen (Fig. 2); two scans were taken and the procedure repeated for the right RA. The mean of two measurements was recorded. Mean values for right and left RA were combined, the mean calculated and used for analysis. Cross-sectional area of rectus abdominis: The circumference of RA was traced around the inside of its border using the on-screen cursor and the CSA computed.

Thickness of rectus abdominis: This was measured vertically at the mid-point of the width of the belly, between the inside edges of the superior and inferior fascial borders. Shape value (indirect width measurement) of RA: True linear width (W) of postpartum RA was not always possible to measure because the shape of some muscles (particularly at Day 1) made it difﬁcult to bisect the muscle using on screen callipers; however, the shape of the RA was approximately an ellipse (Fig. 2). The area of an ellipse is calculated from the formula Area ¼ pAB where A is the semi-major axis (width ¼ W) and B is the semi-minor axis (thickness ¼ T) (Fig. 3). Consequently, the width can be calculated if the CSA and thickness are known and a shape variable (S) can be derived. Therefore if A ¼ width/2 ¼ W/2 and B ¼ thickness/2 ¼ T/2 Area ¼ pðW =2ÞðT=2Þ ¼

pWT ¼ CSA 4

and CSA=T 2 ¼

pW p W ¼ . 4T 4T

Therefore S ¼ CSA/T2 is proportional to the ratio of W/T and can be used to describe the cross-sectional shape of a muscle. For the purposes of this paper, S has been deﬁned as the ‘shape variable’ and it can be seen that the larger the shape variable, the wider and thinner the muscle cross-section, in this case RA, would be. If the CSA of RA were a true ellipse then S would be p/4 and the width would be CSA/(Tp/4), but since the crosssection of the RA muscles scanned only approximated an ellipse, the widths estimated this way are themselves

Fig. 1. Ultrasound images showing the inter-recti distance (IRD) and linea alba (LA) between the medial ends of the right and left rectus abdominis (RA) muscles in cross section. (A) A control subject and with thick LA and an IRD of approximately 1 cm. (B) A postnatal subject with a thin LA and an IRD of approximately 2.6 cm. *Medial borders of the left and right rectus abdominis.

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115

Fig. 2. Ultrasound images of the left rectus abdominis (RA) muscle showing the cross-sectional area in (A) a control subject—external oblique (EO) internal oblique (IO) and transversus abdominis (TA) are seen on the right side of the image forming the aponeurosis around RA. (B) A postnatal subject at Day 1—width of RA is almost that of the probe and the lateral abdominal muscles cannot be seen on the right side of the image. *Medial and lateral borders of RA.

B

A

Fig. 3. Ellipse with semi-major axis of length A and semi-minor axis of length B. The area of an ellipse is calculated from the formula: Area ¼ pAB, where A is the semi-major axis (width ¼ W) and B is the semi-minor axis (thickness ¼ T). Consequently, the width can be calculated if the CSA and thickness are known and a shape variable (S) can be derived. Thus the formula S ¼ CSA/T2 is proportional to the ratio of W/T and can be used to describe the cross-sectional shape of a muscle. Therefore the larger the shape variable, the wider and thinner the muscle (in this case rectus abdominis) would be.

only approximate. Nonetheless the shape constant [S] and the estimated widths were useful for establishing whether the relationship between width and thickness altered during the postpartum period and to investigate how they compared with controls over the postpartum follow-up period. Inter-recti distance: The probe was placed over the midline of the abdomen with the lower border just cephalad to the umbilicus. The medial ends of the two RA muscle bellies were identiﬁed and the gap between the two was measured. 2.5. Data analysis Cross-sectional data: Due to the partial longitudinal design of the study, ANOVAs were not performed on data for the postnatal groups, as some but not all

individuals, contributed to more than one group. Student’s unpaired two-tailed t-tests were used to compare CSA, thickness, shape value and IRD between the control group and each of the four postnatal groups. Signiﬁcance level for all tests was set at Po0.05. Repeated measures: Because the pattern of change in individuals over time may be distorted by plotting group means, repeated measures analysis was used. This included those who contributed at least two measurements over time. The analysis consisted of ﬁtting individual regression line models to each individual’s data, but constraining them to be parallel. This common slope of the regression lines, indicating change in muscle size over time (rate of change per month), was calculated for RA CSA, thickness, shape (width) (df ¼ 67) and IRD (df ¼ 62). The signiﬁcance level for testing the value of the gradient of the slope against zero was set at Po0.05.

3. Results RA was signiﬁcantly thinner, wider (had a higher shape value) and had a larger IRD at 12 months postpartum compared with controls, whilst the CSA was larger at Day 1 postpartum only, and was similar to that of controls after 8 weeks. 3.1. Cross-sectional data 3.1.1. Cross-sectional area of RA The CSA of Day 1 postnatal group (PN1) only was signiﬁcantly greater (Po0.0001) than that of controls (CTL) (CTL: 5.2870.97 cm2, n ¼ 69; PN1: 6.557 1.43 cm2, n ¼ 63) (Table 2 and Fig. 4).

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Table 2 Rectus abdominis thickness, cross-sectional area, shape ratio and inter-recti distance during the ﬁrst postnatal year Group

n

Thickness (mm)

CSA (cm2)

CTL

69

9.77 (1.62)

5.28 (0.97)

PN1

63

8.09 (1.40)***

6.55 (1.43)***

PN2

54

7.97 (1.44)***

PN3

39

PN4

26

Shape value (arbitrary units) 5.74 (1.41)

IRD (mm)

11.17 (3.62)

10.38 (2.55)***

42.22 (20.28)***

5.02 (1.05)

8.26 (2.19)***

22.84 (9.44)***

8.44 (1.48)***

4.93 (0.95)

7.25 (1.99)***

20.73 (7.31)***

9.03 (1.64)*

5.09 (1.11)

6.44 (1.35)*

23.32 (8.38)***

Mean values (71 SD) for thickness, cross-sectional area (CSA), shape value (width) and inter-recti distance (IRD) of RA for control (CTL) and postnatal (PN) groups. Differences between CTL and PN values were tested using two tailed unpaired t- tests. At 12 months postpartum RA was signiﬁcantly thinner and wider (had a larger shape value) and a larger IRD than controls but CSA was larger at Day 1 postpartum only. *Signiﬁcantly different from controls *Po0.05 ***Po0.0001. Post-natal groups: PN1 ¼ Day 1; PN2 ¼ 8 weeks; PN3 ¼ 6 months; PN4 ¼ 12 months.

a

b

11

7 CSA (cm2)

Thickness (mm)

10

9

c

CTL

PN1

PN2

PN3

4

PN4

CTL

PN1

PN2

PN3

PN4

d

12

50 40 IRD (mm)

10 Shape value

6

5

8

7

8

8

6

30 20 10

4 CTL

PN1

PN2

PN3

PN4

0

CTL

PN1

PN2

PN3

PN4

Fig. 4. Cross-sectional data for rectus abdominis (RA) characteristics in control and postnatal groups at different times over the ﬁrst postnatal year (means795% conﬁdence limits for: (a) thickness (mm), (b) cross-sectional area (CSA; cm2), (c) shape value (arbitrary units) (indirect width measurement), (d) inter-recti distance (IRD; mm). Time postpartum—PN1 ¼ Day 1, PN2 ¼ 8 weeks, PN3 ¼ 6 months, PN4 ¼ 12 months. *Signiﬁcantly different from controls; ***Po0.0001; *Po0.05.

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3.1.2. Thickness of RA In all four postnatal groups, RA was signiﬁcantly thinner than in controls (PN1, PN2, PN3 groups Po0.0001; PN4 group P ¼ 0.0478; Table 2 and Fig. 4). 3.1.3. Shape value (width) of RA RA became wider and thinner during pregnancy. The mean value for shape (S) of the control group was signiﬁcantly smaller than in each of the four postnatal groups (PN1, PN2, PN3 Po0.0001; PN4 P ¼ 0.0326; Table 2 and Fig. 4). 3.1.4. Inter-recti distance The IRD in all four postnatal groups was signiﬁcantly greater (Po0.0001) than in controls (Table 2 and Fig. 4), suggesting that it did not return to normal values by 12 months postpartum. 3.2. Longitudinal data: changes over 12 months postpartum

117

3.2.3. Shape value (width) of RA Repeated measures analysis revealed that the shape value (width) became signiﬁcantly smaller (Po0.0001) during the 12 months postpartum (Table 3) with strong evidence of curvature (P ¼ 0.0003), i.e. the initial width of RA at Day 1 postpartum was greater than controls followed by a steady decrease at 8 weeks postpartum that ﬂattened off by 6–12 months and did not return to those of controls at 12 months (Fig. 5). 3.2.4. Inter-recti distance Linear regression analysis showed that the IRD became signiﬁcantly smaller during the 12 months postpartum (P ¼ 0.0002) (Table 3) with strong evidence of curvature (P ¼ 0.0003), i.e. the initial IRD values at Day 1 postpartum were greater than those of controls with a sharp decrease in values at 8 weeks postpartum. These values plateaued at 8 weeks and did not return to those of controls at 12 months (Fig. 5).

4. Discussion

3.2.1. Cross-sectional area of RA Regression analysis revealed that the CSA became signiﬁcantly smaller during the 12 months postpartum (P ¼ 0.0021) (Table 3) with strong evidence of curvature (P ¼ 0.0001), i.e. the initial CSA values at Day 1 postpartum were greater than controls, followed by a sharp decrease at 8 weeks, returning to similar values to those of controls (Fig. 5). 3.2.2. Thickness of RA Regression analysis demonstrated that RA became steadily signiﬁcantly thicker over the 12-month period (P ¼ 0.0003; Table 3) but values did not return to those of controls (Fig. 5).

Alteration in RA thickness, shape (width) and IRD occurred during the study period and none of these variables had returned to control values by 12 months postpartum. Only the CSA had returned to normal over an 8-week period. 4.1. Change in shape of rectus abdominis Maintenance of a thinner and wider RA muscle postpartum suggests that stretch-induced changes occur during pregnancy in the contractile and connective tissue components of the muscle belly, fascial aponeurosis surrounding RA and the underlying transversalis fascia.

Table 3 Repeated measures of rectus abdominis thickness, shape ratio and inter-recti distance Muscle characteristic

Thicknessa CSAa Shapea (width) IRDc

Units

mm cm2 arbitrary units mm

Gradient (b) estimated change per month

0.08651 0.08237 0.288 1.458

95% CLs

Low

High

0.04164 0.1328 0.370 2.193

0.1314 0.03191 0.206 0.7233

t

P

3.78 3.20 6.92 3.89

0.0003b 0.0021b 0.0001b 0.0002b

Rate of change per month (plus 95% conﬁdence limits—CLs) of RA thickness, cross-sectional area (CSA), shape value (width) and inter-recti distance (IRD) during the 12 months post-partum. RA became signiﬁcantly thicker and narrower during the 12-month period whereas the CSA and IRD became signiﬁcantly smaller. These changes per month were all signiﬁcantly different from zero. The t values from unpaired t-tests are shown with signiﬁcance (P) values. n ¼ 45. a df ¼ 67. b Gradient signiﬁcantly different from zero. c df ¼ 62.

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118

a

b

16 14

12 10

***

10 8 6

RA CSA (cm2)

Thickness (mm)

12 8

***

6 4

4 2

2 0

0 0

14

20

0

d

16

12

140

100

14

***

12 10 8

***

80 60 40

6 4

20

2 0

2 4 6 8 10 Time since delivery (months)

120

18

IRD (mm)

Shape Value/Width (Arbitrary units)

c

2 4 6 8 10 12 Time since delivery (months)

0 0

2 4 6 8 10 Time since delivery (months)

12

0

2 4 6 8 10 Time since delivery (months)

12

Fig. 5. Repeated measures results for rectus abdominis showing changes in thickness, cross-sectional area (CSA), shape value (width) and inter-recti distance (IRD). The data set in black on the left of the plots is that of the control group, the remaining four data sets in grey are those of the four postnatal groups. a ¼ RA thickness. The bold extended line is the ﬁtted line for a representative subject to illustrate the average slope obtained from least-squares regression analysis ﬁtting separate but parallel straight lines to every subject. Since every subject was allowed their own intercept, their trend line equations were different even though the slope was same. The general formula is: Muscle thickness ¼ individual starting value+b.time in months since delivery, where b is the same for every subject (b ¼ beta). No evidence of a signiﬁcant curvilinear tend was seen. ***Slope signiﬁcantly different from zero Po0.0001. b ¼ CSA, c ¼ shape value (width) and d ¼ IRD. The bold curved line on the plots is the ﬁtted line for a representative subject to illustrate the average-ﬁtted curved trend from least-squares regression analysis ﬁtting separate but parallel curved lines to every subject. The general formula is: muscle variable (CSA, Shape or IRD) ¼ individual starting time+b1.time+b2.time2 (where time is time in months since delivery). ***Signiﬁcant curve Po0.0001.

There could be a selective hypertrophy of Type I ﬁbres in response to stretch, as suggested by animal studies. Prolonged muscle stretch in rats produced activation of slow genes and repression of fast Type IIx genes (Goldspink et al., 1991). In the RA of pregnant rats the diameter of slow Type I ﬁbres increased in the latter half of pregnancy while that of the fast glycolitic ﬁbres (Type IIX) decreased, with no change to the Type IIA ﬁbres (Martin, 1979). In contrast, both Types I and II ﬁbres increased in diameter in porcine and rabbit studies, with a concomitant increase in the number of Type I ﬁbres and decrease in Type II ﬁbres (Lalatta et al., 1987, 1988). Since these studies were performed on different animal species, it is not known how results translate to humans but it seems that alterations in RA muscle ﬁbre types might occur during pregnancy.

Prolonged stretch is known to increase the number of sarcomeres in series at the ends of muscle (Williams and Goldspink, 1978) with increased protein synthesis and addition of myotubes (Dix and Eisenberg, 1990), resulting in an increase in total muscle volume. It is possible that this mechanism occurs in postnatal women and the addition of sarcomeres in series to RA could reduce the ability of postpartum women to perform trunk ﬂexion and hold an inner range contraction. The combination of ﬁbre type and architectural changes may also reduce the ability of RA to produce active tension. However following damage or exercise, skeletal muscle is able to repair itself by replenishing cell nuclei from satellite cells stimulated by the action of a local tissue repair mechanism, the mechanogrowth factor (Goldspink, 2006). The effects of stretch on postnatal

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abdominal muscle have not yet been investigated histochemically and would be the subject of further study. Anecdotally, many women reported feeling a ‘‘lack of support’’ in their abdomen. This could be caused by a change in fascia as well as muscle. Prolonged stretch of the tibialis anterior in rats produced increased deposition of collagen Type III, damage to the perimysial and endomysial network and indicated that intramuscular connective tissue did not adapt to stretch as well as the contractile components (Williams et al., 1998). Further study into the effects of prolonged stretch on different types of connective tissue in pregnancy and factors affecting recovery are indicated. Measurement of the width of RA on the ultrasound image in control subjects using on-line callipers was straightforward as the muscle cross-section is approximately elliptical. Thus, the approximate ratio of width to thickness was easy to calculate. As the RA appeared to be wider and thinner in most Day 1 postpartum subjects and it was not known whether this disproportion continued further into the postpartum period, it was decided to explore this width/thickness ratio further. However, it was not always possible to bisect the RA and establish width because its shape was not so regular. An approximate estimate of width was therefore derived from the formula for establishing the area of an ellipse (see Fig. 3). This approach to estimation of width to thickness ratio has not been used in any studies on postnatal RA muscles and from the present results it is recommended that the formula be used in future studies of this subject group when width cannot be measured accurately. 4.2. Cross-sectional area of RA As the CSA was larger than in controls in Day 1 postpartum subjects, it could be assumed that there was hypertrophy of RA during pregnancy, perhaps in response to bearing an increased load. A healthy muscle would show low echogenicity on ultrasound imaging, i.e. it would be darker (Stokes et al., 1997). Increased echogenicity of the contractile parts of muscle has been found in patients with age-related deterioration (Maurits et al., 2003), denervated muscles (Gunreben and Bogdahn, 1991) or myopathic muscles (Lamminen, 1991; Udd et al., 1991; Maurits et al., 2003), whereas with neuropathic muscles there is inhomogeneity due to pathological disruptions of muscle architecture (Zuberi et al., 1999; Maurits et al., 2003). In the current study, observations on RA appearance were not analysed quantitatively, but visual assessment suggested that some postnatal RA muscles showed inhomogeneity and areas with some increased echogenicity. High echogenicity has been attributed to inﬁltration of noncontractile tissue such as fat or collagen (Reimers et al.,

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1993; Elliott et al., 2005). It is not possible to determine whether there was any neuropathy present in RA but it is interesting to note that it has been suggested that stretch-induced denervation of the abdominal wall may occur during pregnancy and delivery (Stelzner et al., 1993). Therefore increased CSA at Day 1 postpartum may reﬂect replacement of muscle tissue with fat and connective tissue rather than hypertrophy of muscle ﬁbres. 4.3. Implications for muscle strength Long-term change in muscle thickness and width may affect the strength of RA but strength of individual abdominal muscles cannot be measured directly. Alteration in the ratio between thickness and width of the quadriceps in patients with myositis was associated with abnormal muscle properties and a decrease in muscle force (Chi-Fishman et al., 2004). This ﬁnding could be extrapolated to the current study, implying that alteration in thickness and width postnatally could result in a reduced force generation capacity. Trunk ﬂexion exercises are known to recruit RA (Sarti et al., 1996; Negrao Filho et al., 2003; Clark et al., 2003) and an attempt to perform a trunk curl at 8 weeks after delivery was reported to be successful or moderately successful in 5 out of 6 women (Gilleard and Brown, 1996) and successful in 80% at 6 weeks (Spence, 1978). However, these two studies used qualitative measurement tools and a robust study of postpartum trunk ﬂexor strength is required. Using isokinetic dynamometry, Potter et al. (1997b) found that concentric and eccentric trunk ﬂexion strength was signiﬁcantly lower in women at 24 weeks postpartum than in controls. The reduction in RA thickness found in the current study indicates a decrease in strength. If this were the case, study of the effect of postnatal exercise programmes that do not load the spine would be informative. Repeated measures analysis demonstrated that RA recovery of CSA, shape and thickness continued during the 12-month postpartum period. Further study of the time for full recovery of thickness and shape postpartum is indicated. 4.4. Inter-recti distance The IRD postpartum was signiﬁcantly wider than in controls in all four postnatal groups but most recovery occurred between Day 1 and 8 weeks, when the IRD reached a plateau. The mean IRD at 12 months was 22.3 mm, but measurements ranged from 10.2 to 42.1 mm with a third of subjects presenting with a wider gap than the mean. Deﬁnitions of the width of a postnatal diastasis of RA (DRA) at the umbilicus using external skin markers

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vary. It has been deﬁned as a width of 41.5 cm (Gilleard and Brown, 1996), 42 cm (Potter et al., 1997a; Lo et al., 1999), 42.5 cm (Candido et al., 2005) or 42 ﬁnger widths during a partial sit-up (Bursch, 1987; Sheppard, 1996). DRA has been noted by the 26th week of gestation (Gilleard and Brown, 1996) and in 66% of women during the third trimester (Boissonnault & Blaschak). Previous studies have noted that there is a partial resolution of a DRA by 4 weeks (Gilleard and Brown, 1996) and 8 weeks (Boissonnault and Blaschak, 1988) postpartum and these ﬁndings agree with those of the current study. Risk factors have been found to include multiparity, maternal age (434 years), larger babies, greater weight gain, caesarean section and multiple gestation (Lo et al., 1999). This has been disputed by Candido et al. (2005) who found that women with a diastasis were more likely to be providing child care (although the nature of child care was not speciﬁed) and there was an association with Caucasian ethnicity and a lack of regular exercise during pregnancy. It is suggested that those with DRA may have a reduced capacity for force generation. In support of this hypothesis, in a small study of six subjects at 8 weeks postpartum, subjects with a DRA of 435 mm were signiﬁcantly less successful at performing a pelvic tilt or a trunk curl than those without a DRA (Gilleard and Brown, 1996). Together with the persistence of decreased thickness and increased width of RA plus potential changes to the fascia surrounding RA at 12 months postpartum; an increased IRD/DRA may lead to decreased anterior abdominal wall stiffness and a possible mechanical disadvantage. These changes in passive stiffness might lead to muscle imbalance and thus poor co-ordination with the other three abdominal muscles due to their connections to RA via the surrounding aponeurosis and the linea alba. These ﬁndings have implications for postnatal exercises and the identiﬁcation of factors that reduce a persistent DRA, increase RA thickness and reduce RA width would be valuable.

4.5. Limitations of the study The main limitation of the study was the discrepancy between cross-sectional and longitudinal subject numbers. Given the time frame of this project, a full longitudinal study could not be undertaken. In addition, a proportion of the women became pregnant again in less than 1 year, some moved from the area and others returned to work, hence many could not attend a followup appointment. As the results from the limited longitudinal data showed change in characteristics of RA during the 12-month postnatal period, a further longitudinal study using greater numbers is indicated.

5. Conclusions Characteristics of RA thickness and width, and the IRD had not returned to normal values by 12 months postpartum. A thinner, wider and longer RA has implications for strength and fascial support. Persistent increased IRD may cause decreased stiffness of the anterior abdominal wall and predispose to a mechanical disadvantage. Studies of the postpartum histochemical and architectural changes, trunk ﬂexion tension and production would inform the development of effective postnatal exercise programmes. Exercises that target the return of normal IRD, RA width, thickness and length without loading and compressing the lumbar spine are required.

Acknowledgements The authors thank the subjects who took part in the study, Dr. Anthony Swan for statistical advice, Dr. Basky Thilaganathan for use of facilities in the Fetal Medicine Unit at St. George’s Hospital, London and the Neuro-disability Research Trust for ﬁnancial support. Part of this work was undertaken at the Royal Hospital for Neuro-disability, which received a proportion of its funding from the NHS Executive; the views expressed in this publication are those of the authors and not necessarily those of the NHS Executive. References Boissonnault JS, Blaschak MJ. Incidence of diastasis recti abdominis during the childbearing year. Physical Therapy 1988;68(7):1082–6. Bottinelli R, Pellegrino MA, Canepari M, Rossi R, Reggiani C. Speciﬁc contributions of various muscle ﬁbre types to human muscle performance: an in vitro study. Journal of Electromyography and Kinesiology 1999;9:87–95. Bursch SG. Interrater reliability of diastasis recti abdominis measurement. Physical Therapy 1987;67(7):1077–9. Caix M, Outrequin G, Descottes B, Kalfon M, Pouget X. The muscles of the abdominal wall: a new functional approach with anatomoclinical deductions. Anatomia Clinica 1984;6:101–8. Candido G, Lo T, Janssen PA. Risk factors for diastasis of the recti abdominis. Journal of the Association of Chartered Physiotherapists in Women’s Health 2005;97(Autumn):49–54. Chi-Fishman G, Hicks JE, Cintas HM, Sonies BC, Gerber LH. Ultrasound imaging distinguishes between normal and weak muscle. Archives of Physical Medicine and Rehabilitation 2004;85(6):980–6. Clark KM, Holt LE, Sinyard J. Electromyographic comparison of the upper and lower rectus abdominis during abdominal exercises. Journal of Strength and Conditioning Research 2003;17(3):475–83. Dix DJ, Eisenberg BR. Myosin mRNA accumulation and myoﬁbrillogenesis at the myotendinous junction of stretched muscle ﬁbers. Journal of Cell Biology 1990;111(5, Part 1):1885–94. Elliott JM, Galloway GJ, Jull GA, et al. Magnetic resonance imaging analysis of the upper cervical spine extensor musculature in an asymptomatic cohort: an index of fat within muscle. Clinical Radiology 2005;60:355–63.

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Manual Therapy 13 (2008) 122–131 www.elsevier.com/locate/math

Sensorimotor disturbances in chronic neck pain—Range of motion, peak velocity, smoothness of movement, and repositioning acuity Per Sjo¨landera,b,, Peter Michaelsonb,c,d, Slobodan Jaricb,e, Mats Djupsjo¨backab a

Southern Lapland Research Department, Postgatan 7, SE-912 32 Vilhelmina, Sweden Centre for Musculoskeletal Research, University of Ga¨vle, SE-907 12 Umea˚, Sweden c Department of Surgery and Perioperative Sciences, Division of Sports Medicine, University of Umea˚, SE-901 87 Umea˚, Sweden d Department of Health Science, Physiotherapy Unit, Lulea˚ University of Technology, SE-971 87 Lulea˚, Sweden e Human Performance Laboratory, University of Delaware, DE 19716, USA b

Received 9 November 2004; received in revised form 22 June 2006; accepted 20 October 2006

Abstract The purpose of this pilot study was to evaluate sensorimotor functions in patients with chronic neck pain with objective and quantitative methods. A group of 16 patients with chronic idiopathic neck pain of insidious onset or whiplash associated disorders (WAD) was compared to an equally sized group of healthy subjects. Kinematics were investigated during voluntary head rotations by measuring range of motion, variability of range of motion (ROM-Variability), peak velocity, and smoothness of movement (jerk index). Repositioning acuity after cervical rotations was evaluated by analysing constant and variable error (VE). In comparison to the healthy subjects, the patients showed signiﬁcantly larger jerk index, ROM-Variability and VE. No statistically signiﬁcant differences were found between insidious neck pain and WAD. It is concluded that jerky and irregular cervical movements and poor position sense acuity are characteristic sensorimotor symptoms in chronic neck pain. The observed individuality in sensorimotor disturbances emphasizes the importance of developing speciﬁc rehabilitation programs for speciﬁc dysfunctions, and of using objective and quantitative methods for evaluation of rehabilitation. r 2006 Elsevier Ltd. All rights reserved. Keywords: Neck pain; Whiplash; Neck kinematics; Motor control; Proprioception; Jerk

1. Introduction In clinical practice, patients with chronic neck pain often show reduced range of motion (ROM), disturbed movement precision, and slow and jerky head movements. While reduced ROM, slow movement and large joint position errors have been documented by objective methods in chronic neck pain (Revel et al., 1991; Osterbauer et al., 1996; Feipel et al., 1999; Dall’Alba et al., 2001; Rix and Bagust, 2001; Kristjansson et al., 2003; Treleaven et al., 2003; O¨hberg et al., 2003; Corresponding author. Southern Lapland Research Department, Postgatan 7, SE-912 32 Vilhelmina, Sweden. Tel.: +46 940 14494; fax: +46 940 15353. E-mail address: [email protected] (P. Sjo¨lander).

1356-689X/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2006.10.002

Madeleine et al., 2004), smoothness of movement has not been previously assessed with objective measurements on such patients. Moreover, studies of repositioning errors show partly contradictory results, some demonstrating signiﬁcantly larger errors in neck pain while others found no differences in comparison to asymptomatic subjects (Revel et al., 1991; Rix and Bagust, 2001; Kristjansson et al., 2003; Treleaven et al., 2003; Madeleine et al., 2004). One way of quantitatively evaluate smoothness of movement is to measure movement jerk, i.e. changes of acceleration (Hogan, 1984; Wolpert et al., 1995). Several studies have demonstrated that poor movement control, as in e.g. children and patients with neurological diseases, is associated with high jerk cost (Yan et al., 2000; Contreras-Vidal and Buch, 2003). Since there are

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motor control disturbances in patients with chronic neck pain, it is possible that this could cause jerkier movements. In attempts to investigate proprioceptive disturbances in patients with chronic neck pain, a number of studies have measured repositioning errors after cervical rotations (Revel et al., 1991; Rix and Bagust, 2001; Kristjansson et al., 2003; Treleaven et al., 2003; Madeleine et al., 2004). The partly contradictory results has been suggested to be due to differences in methods applied for error estimation (Rix and Bagust, 2001) and, in some studies to results based on very few trials (Allison and Fukushima, 2003). Moreover, common to most of these studies is that the average absolute error of a set of trials was used as the outcome variable. Absolute error is a non-linear combination of constant (CE) and variable error (VE). In a repositioning task, CE represents the mean deviation from the target, also denoted the ‘point of subjective equality’ (Gescheider, 1997), while VE represents the variability of the matching trials around the CE (Gescheider, 1997). There is evidence that CE reﬂects intrinsic systematic biases in the motor control system, and that VE is the result of the acuity of sensorimotor processes, i.e. the position sense acuity (Clark et al., 1995). Notably, according to psychophysical literature, the latter is in line with the general deﬁnition of sensory discrimination threshold in an adjustment tasks (Gescheider, 1997). Thus, separate analyses of CE and VE could contribute to resolve the controversy on whether large repositioning errors are a signiﬁcant characteristic in chronic neck pain, and increase our understanding of the mechanisms underlying repositioning errors after cervical rotations.

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To increase the knowledge on sensorimotor dysfunctions in chronic neck pain, and of the mechanisms underlying them, the objective of this pilot study was to objectively and quantitatively evaluate sensorimotor functions during cervical rotations by measuring ROM, peak velocity, movement jerk, constant and variable repositioning errors. In order to assess possible effects of aetiology, two groups of patients and one group of healthy subjects were investigated.

2. Methods The study was designed as a single blinded, controlled comparative group study, and it was approved by the ethics committee of the Faculty of Medicine at Umea˚ University. 2.1. Subjects All patients who entered the rehabilitation programme at Saxna¨sga˚rden Rehabilitation Centre during the second half of 2001 were offered participation in the study. The inclusion criteria were neck pain with a duration of at least six months. Exclusion criteria were neurological disease, signs of brain damage, impairment of the vestibular system, rheumatic disease and severe pain in other body regions. A physician, specialist in rehabilitation medicine, executed the selection procedure based on physical examinations and medical records. In total, 16 patients were selected (Table 1). After being thoroughly informed about the study, all gave their written consent to participate.

Table 1 Anthropometric data, pain characteristics and neck disability index (NDI) of two groups of patients with chronic neck pain and of a corresponding group of asymptomatic subjects Characteristics

Control (n ¼ 16)

Insidious neck pain (n ¼ 9)

WAD (n ¼ 7)

Men Women Age (years) Height (cm) Weight (kg) Pain duration (months) Pain intensity (mm)a NDI

3 13 41 (9) 168 (8) 70 (14)

0 9 40 (9) 165 (7) 73 (18) 97 (68) 52 (16) 37 (11)

2 5 45(11) 170 (10) 79(13) 76(84) 45(19) 44(23)

2 1

4 5

Vertigob Unsteadinessb

F

0.6 0.7 0.9 0.2 0.9 0.7 Fisher exact test 2.0 6.1

Mean values with standard deviation in brackets, except for the distribution of men and women in each groups and the prevalence of vertigo and unsteadiness which are given in number of persons. For age, height, weight, pain duration, pain intensity and NDI F-values are shown for ANOVAmodels. Vertigo and unsteadiness was evaluated using Pearson Chi-square test (Fisher exact test). a Average pain intensity over the last week was assessed on a blank 100-mm visual analogue scale, where 0 mm corresponded to ‘no pain at all’ and 100 mm to ‘the worst imaginable pain’. b Number of patients who reported frequent episodes of vertigo and unsteadiness. po0.05.

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For seven patients the primary aetiology of the neck pain was a whiplash trauma (in short, WAD), and according to the criteria of the Quebec Task Force classiﬁcation they were graded as II or III (Spitzer et al., 1995). When entering the study, ﬁve patients demonstrated neurological signs such as muscle weakness, paresthesia, pin-prick sensations and brachialgia. However, to what extent these symptoms were caused by the initial trauma or had developed over time (due to e.g. senitization mechanisms) could not be determined for some of these patients. Thus, as the medical records from the acute phase after the injury were insufﬁcient no attempt was made to sub-divide the WAD group into grade II and III. The other nine patients demonstrated idiopathic neck pain of insidious onset (in short, insidious neck pain). Eight of these claimed that their neck pain was workrelated, while the aetiology was uncertain according to one patient. A control group was recruited from the local community and compiled to match the 16 patients by age and gender (Table 1). The inclusion criteria for the control group were absence of current, previous (over the last year) or repeated periods of neck pain, dizziness and vertigo. They were also ineligible if they complied with any of the exclusion criteria for the patients. 2.2. Apparatus Movements of the cervical spine were measured with an electromagnetic tracking system (FASTRAKTM, Polhemus Inc, USA). This system has previously been demonstrated to have good reliability in studies of cervical motion (Pearcy and Hindle, 1989). The motion of the head relative to the trunk was obtained by using two receivers, one positioned on the forehead by a specially constructed helmet and the other taped on the skin above the dorsal spinal process of Th1. Each receiver recorded both the position (in Cartesian coordinates) and the orientation (Euler angles). The sampling rate was 60 Hz and all data was collected on a PC. 2.3. Procedures The functional disability for the patients was evaluated using the Neck Disability Index (NDI) (Vernon and Mior, 1991) computing the score up to 100. Average pain intensity over the last week was assessed on a blank 100-mm visual analogue scale, where 0 mm corresponded to ‘no pain at all’ and 100 mm to ‘the worst imaginable pain’. The frequency of vertigo and unsteadiness was indicated separately on scales with six alternatives ranging from ‘never’ to ‘very often’. The patients were considered to suffer from vertigo and/or

unsteadiness if the incidence was rated as ‘rather often’, ‘often’ or ‘very often’. The sensorimotor evaluation was completed before the rehabilitation programme started. In addition to the head rotation test, the patients performed standardised tests of standing balance and cervical stability (Michaelson et al., 2003). The entire test procedure was completed within one hour. The tests were conducted in a quiet, undisturbed room. The cervical rotations were performed with closed eyes in standing posture. The subjects stood barefooted with their feet in parallel and the arms crossed over their chest. The same experimenter, who was blinded to the subjects’ neck pain status, executed all tests. The instructions given to the subjects during the tests were pre-recorded on tape in order to provide identical instructions and time schedule for all subjects. The subjects were encouraged to take a break whenever they felt increased pain or fatigue, or when their focus on the task declined. Before the test session started, the subjects were instructed to ‘comfortably rotate the head as fast and far as possible’. The head rotation was performed in two separate conditions, rotation to the right and to the left. In each condition, a set of eight consecutive rotations (trials) was executed with a short resting interval between each. Prior to each set of head rotations the subjects where instructed to ‘memorize the starting position’, which was a self-selected neutral position of the head, and to ‘reproduce this position as accurately as possible after each head rotation’. The sets of cervical rotations and the tests of standing balance and head stability were performed in random order.

2.4. Data processing and analyses Custom made software was used to organize the data, and MatLab-code was written for the calculations (ver 5.3, 1999, MathWorks Inc., USA). All kinematic parameters were calculated from the orientation of the head in relation to the trunk. First, the data was transformed so that the z-axis of the receivers were set in parallel to the vertical axis when the head was in the starting position, and then, in order to maximize the range of rotations, the data was transformed by an algorithm that slightly adjusted the orientation of the coordinate system of the receivers. After these adjustments the rotation of the head around the z-axis was at least one order of magnitude larger than for the other two axes and therefore considered as rotation around a single axis. The angular data was low-pass ﬁltered with a cut-off frequency of 10 Hz. A quintic spline (generalized cross-validatory spline, Woltring, 1986) was used to allow for the three steps of differentiation needed to calculate movement jerk.

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Fig. 1. Examples of position, velocity, acceleration and jerk recorded from a control subject and a patient with insidious neck pain during the cervical rotation test. Dotted lines indicate the start and the stop of the rotations.

The start and the stop of rotation were deﬁned as the time when the angular velocity passed 5% of peak velocity (Fig. 1). The peak velocity was deﬁned as the maximum absolute value of the differentiated angular data. Jerk index was calculated using the algorithms described by Kitazawa et al. (1993), which normalizes the jerk cost with respect to angular excursion and movement time. Thus, the jerk index, Cj, was calculated as sﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃ n 1X t5 Cj J 2i 2 i¼1 D

CE was calculated as the mean value of the algebraic errors (Schmidt and Lee, 1999), thus indicating the degree of over- or under-shooting of the target position. The VE was calculated as the standard deviation of the algebraic errors (Schmidt and Lee 1999), and hence reﬂected the variability of the repositioning. The variability of the ﬁnal position of the outward head rotations was assessed from the average standard deviation of the individual subject’s cervical rotations (ROM-Variability).

where J is the vector of the jerk values over the movement (calculated from the kinematic data, as described above), n the number of samples of the vector, i the vector index, t the movement time, and D the movement distance. Peak velocity and jerk index were calculated separately for outward rotation to the right (Out-Right), inward rotation from the right (In-Right) outward rotation to the left (Out-Left) and inward rotation from the left (In-Left). The repositioning acuity (VE) and bias (CE), ROM and the variability of ROM (ROM-Variability) were separately analysed for right and left rotations. Repositioning VE and CE were calculated as follows: For each trial the algebraic repositioning error was calculated as the difference between the target position and the position reached after the cervical rotation. The

Differences between the groups were evaluated by multivariate analyses of variance (MANOVA) and multivariate analysis of covariance (MANCOVA; ROM as covariate). The latter was done to adjust for, and to evaluate, potential effects of reduced ROM on peak velocity, repositioning errors and ROM-Variability (Neufeld, 1981). To compare results between the groups regarding the speciﬁc conditions (Out-Right, In-Left etc.), one-way analysis of variance (ANOVA) and one-way analysis of covariance (ANCOVA; ROM as covariate) were used. For post-hoc tests in ANOVA (ANCOVA), Bonferroni test was used. To ensure that the basic assumptions for MANCOVA and MANOVA were fulﬁlled, all models were tested with Box’s test of equality of covariance matrices, and Levene’s test of equality of error variances (for ANOVA, ANCOVA).

2.5. Statistics

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If any of these tests showed signiﬁcant results, the variables were transformed using natural logarithms. These transformations resulted in a non-signiﬁcant Levene’s test of equality of error variances. Outliers were identiﬁed by Cook’s distance test and excluded from the analyses. This occurred in the MANOVAmodel for ROM for one patient with insidious neck pain, in the MANCOVA-model for CE for one patient with WAD, and the MANOVA-model for jerk index for one control subjects. Except for the jerk-model, these models were non-signiﬁcant both before and after the removal of the outliers. For clarity and comparisons only non-transformed data are presented in the result section. The three groups compared in the MANOVA/ MANCOVA-models, and subsequent ANOVA/ANCOVA-models, were the control group, the insidious neck pain group and the WAD group. A p-value of o0.05 was considered as signiﬁcant. All statistics were done using SPSS (ver 11.0, 2001, SPSS Inc, USA).

3. Results In total 32 subjects participated in the study. There were 16 patients with chronic neck pain, 9 patients with insidious neck pain, 7 patients with WAD and 16 control subjects. All patients suffered from long lasting neck pain with moderate to severe pain intensity and functional disability (Table 1). There were no signiﬁcant differences between the three groups (i.e. control, insidious neck pain, WAD) regarding age, weight or height or between the two groups of patients regarding most of the parameters, i.e. pain duration, pain intensity and prevalence of self-reported vertigo. However, the patients with WAD reported a signiﬁcantly higher prevalence of unsteadiness as compared with patients with insidious neck pain (Chi-square, po0.05).

3.1. Range of motion and peak velocity Although the patients on average showed less ROM and lower peak velocity than the controls (Table 2), there were no statistically signiﬁcant differences between the three groups (MANOVA on ROM, right and left: F[4,54] ¼ 1.6, p ¼ 0.19; MANCOVA on peak velocity, in- and outward rotations to the left and right,: F[8,46] ¼ 1.3, p ¼ 0.28, ROM to the left and right as covariates). However, the covariate ROM to the left was signiﬁcant in the model (po0.05) but not ROM to the right (p ¼ 0.38). 3.2. Smoothness of movement Figure 1 shows examples of angular data and its derivatives for two separate trials, one recorded from a control subject and one from a patient with insidious neck pain. The examples demonstrate typical differences between the control subjects and the patients regarding the smoothness of cervical rotations. Qualitatively, this difference is most obvious in the velocity signal, which is clearly more jagged for the patient. Whenever a signal is variable, the root cause of the variability is reﬂected in the derivatives of the signal. Both experimental and modelling studies have presented evidence that such movement variability is best quantiﬁed by calculating the jerk cost (i.e. the rate of change of acceleration; see e.g. Hogan, 1984), and when distance and/or movement time varies, as in the present data, the variability should be expressed as the normalized jerk cost, i.e. the jerk index (Kitazawa et al., 1993). There were signiﬁcant differences between the three groups on jerk index (MANOVA: F[8,50] ¼ 2.5, po0.05). Analysis of the separate directions of rotation with ANOVA showed statistically signiﬁcant differences

Table 2 Range of motion and peak velocity recorded during voluntary cervical rotations to the right and to the left Condition

Range of motion n Right (deg.) Left (deg.) Peak velocity n Out-Right (deg./s) Out-Left (deg./s) In-Right (deg./s) In-Left (deg./s)

Control

Insidious neck pain

WAD

Mean

SD

Mean

SD

Mean

SD

16 70.7 71.9

711.2 713.0

8 57.9 61.8

711.0 710.9

7 67.7 68.5

712.1 712.9

16 120.7 132.8 116.9 119.5

733.1 739.6 728.6 728.6

9 93.1 95.3 85.4 89.7

732.4 727.5 732.4 726.3

6 93.8 108.6 96.4 103.7

729.8 720.4 727.4 719.1

Mean values with standard deviation (SD) are separately shown for the control subjects and the patients with insidious neck pain and WAD. *po0.05.

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Table 3 Jerk index, repositioning acuity (CE ¼ constant error; VE ¼ variable error) and the variability of range of motion (ROM-Variability) from the cervical rotation test Condition

Jerk Index n Out-Right Out-Left In-Right In-Left CE n Right (deg.) Left (deg.) VE n Right (deg.) Left (deg.) ROM-Variability n Right (deg.) Left (deg.)

Control

Insidious neck pain

F

WAD

Mean

SD

Mean

SD

Mean

SD

15 7.7 7.5 9.4 8.6

74.2 74.4 77.1 74.9

9 14.1 15.9 17.3 16.2

79.7 79.5 711.3 78.7

7 13.6 13.1 15.2 11.1

79.1 75.1 710.6 76.1

16 0.1 0.1

70.5 70.6

9 0.4 0.4

70.5 70.8

6 0.4 0.7

70.8 71.1

16 2.0 2.2

70.7 71.0

9 2.9 2.7

71.4 71.0

7 3.3 4.1

71.7 72.2

5.6** 6.1**

16 3.2 4.1

71.3 71.9

9 3.7 4.2

71.5 71.3

7 5.8 6.7

72.3 73.0

8.2** 6.2**

2.7 7.1** 2.1 4.5*

Mean values with standard deviation (SD) are separately shown for the control subjects and the patients with insidious neck pain and WAD. For jerk index, F- and p-values from one-way ANOVA-models are shown, while the F- and p-values for CE, VE and ROM-Variability are given for one-way ANCOVA-models with range of motion as covariate. *po0.05; **po0.01.

between the groups for Out-Left (po0.01) and In-Left (po0.05), but not for Out-Right (p ¼ 0.09) and InRight (p ¼ 0.14) (Table 3). For Out-Left, the post-hoc test revealed signiﬁcantly different jerk indices for the control and the insidious neck pain groups (po0.01) and for the control and the WAD groups (po0.05), but non-signiﬁcant differences between the WAD and the insidious neck pain groups (p ¼ 0.9). For In-Left, the jerk indices for the control and the insidious neck pain groups were signiﬁcantly different (po0.05), while the differences between control and WAD (p ¼ 0.9) and insidious neck pain and WAD (p ¼ 0.4) were nonsigniﬁcant. Beyond the group-mean data, there was a substantial heterogeneity within all three groups. This is clearly demonstrated for jerk index in Fig. 2. The variability in jerk index was larger within the groups of patients than among the control subjects, and the overlap between the groups of patients was considerable.

3.3. Repositioning acuity and bias The CE and the VE were calculated to assess the ability to reproduce a self-selected neutral head position following horizontal cervical rotations. The CE and VE were evaluated by separate MANCOVA-models, with rotation to the right and left as dependent variables and

with ROM as covariates, to control for differences in rotation distance. There were no signiﬁcant differences between the control group, insidious neck pain group and WAD group regarding CE, regardless of the direction of rotation (MANCOVA: F[4,50] ¼ 2.3, p ¼ 0.08, ROM to the left and right as covariates). The MANCOVA-model of VE revealed statistically signiﬁcant differences between the three groups (F[4,52] ¼ 3.9, po0.01). None of the covariates (ROM right, ROM left) were signiﬁcant in the model. The one-way ANCOVA-model for rotations from the right demonstrated statistically signiﬁcant differences between the three groups (po0.01) with ROM right as the covariate (po0.05). The post-hoc tests for rotation from the right were signiﬁcant both between the control and insidious neck pain groups (po0.05) and between the control and WAD groups (po0.05), while there was no signiﬁcant difference between insidious neck pain and WAD (p ¼ 0.9). Also the one-way ANCOVA-model for VE for rotations from the left was signiﬁcant different between the three groups (po0.01) (Table 3), but the covariate ROM left was none signiﬁcant (p ¼ 0.09). For rotation from the left, the post-hoc tests revealed signiﬁcant differences between the control and WAD groups (po0.01) but not between control and insidious neck pain (p ¼ 0.4) or between the insidious neck pain and WAD groups (p ¼ 0.3).

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Jerk Index

30

Control Insidious WAD

20

10

0

Out-Right

Out-Left

In-Right

In-Left

Fig. 2. Box plot demonstrating jerk indices for outward rotation to the right (Out-Right) and to the left (Out-Left), and inward rotation to the right (In-Right) and to the left (In-Left). Data are separately shown for control subjects and patients with insidious neck pain and with WAD. The boxes display the median values and the 25th and 75th percentiles, while the whiskers represent the 10th and 90th percentiles.

3.4. ROM-Variability In order to evaluate the consistency of the ROM, the ROM-Variability was calculated. The MANCOVAmodel revealed statistically signiﬁcant differences between the three groups (F[4,52] ¼ 4.8, po0.05). The covariates ROM to the left and right were nonsigniﬁcant in the model. Both one-way ANCOVAmodels, for rotations to the right (po0.01) and the left (po0.01), showed signiﬁcant differences between the groups (Table 3). Both models were signiﬁcantly inﬂuenced by the covariates (right: po0.05; left: po0.05). The post-hoc test for rotation to the right and left revealed signiﬁcant differences between the control and WAD groups (right: po0.001; left: po0.01). None of the post-hoc test comparing the control group and insidious neck pain group were signiﬁcant (right: p ¼ 0.4; left: p ¼ 0.9), neither was the post-hoc-test comparing the insidious neck pain and WAD groups to the right (p ¼ 0.08) signiﬁcant but to the left (po0.05).

4. Discussion The results of the present study substantiate common clinical observations and, more importantly, demonstrate objective and quantitative methods for identiﬁcation and follow-up of speciﬁc sensorimotor disturbances. It is concluded that jerky and inconsistent cervical movements, together with poor position sense acuity, are important sensorimotor symptoms in chronic neck pain of both traumatic and non-traumatic origin. Patients with insidious neck pain demonstrated the jerkiest movements, while those with WAD showed the poorest repositioning acuity and the largest ROM-

Variability. However, in agreement with previous reports on patients with WAD and insidious neck pain (Kristjansson et al., 2003; Jull et al., 2004), a considerable heterogeneity of the sensorimotor functions was found within the groups of patients (cf. Fig. 2). It is tentatively suggested that the pattern of sensorimotor disturbances in chronic neck pain is very much individual, and not always related to the aetiology of the pain. 4.1. Methodological considerations The patients of the present study were selected from a large group of patients with severe, chronic neck pain and with considerable functional disability due to their neck condition. However, the study is based on small samples of patients which might have caused selection biases. Thus, the small samples prevent any ﬁrm conclusions on general similarities and differences in sensorimotor disturbances between WAD and insidious neck pain. In the present study the order of the different tests were randomised which in a small sample might bias the outcome. To reduce this risk, all tests were nonstrenuous and easy to perform, and the participants were encouraged to take breaks whenever their focus on the task was declining. In contrast to in most other investigations of cervical repositioning acuity we used the ﬁnal position of the previous rotation as the target position, rather than deﬁning a ﬁxed target position to which the patients were guided between each trial (e.g. Kristjansson et al., 2003; Treleaven et al., 2003; O¨hberg et al., 2003). This together with the fact that the cervical rotations were made in a standing posture in the present study and in a sitting posture in most previous studies, might account

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for some of the differences observed between the present and other similar studies (see below). Movements or drift of the target position were compensated for to ensure appropriate error calculations (see Methods). These procedures imply that the effect of learning a given target position was minimized, and, more importantly, that a number of sensorimotor variables could be measured from a single set of rotations (i.e. velocity, ROM, movement irregularities and repositioning errors). In the statistical analyses of peak velocity, ROMvariability, repositioning acuity and bias we used ROM as a covariate since movement distance can inﬂuence repositioning variability (e.g. Neufeld, 1981) as well as the peak velocity of movement. The fact that the covariate was signiﬁcant in several of the statistical models for peak velocity, ROM-Variability and repositioning acuity highlights the need for including ROM as a covariate in repositioning tests where the movement distance is not ﬁxed. 4.2. Range of motion and peak velocity In spite of notably lower ROM between patients with insidious pain and the controls, there were no signiﬁcant differences between the groups. Previous studies have reported signiﬁcant differences of ROM between WAD and asymptomatic subjects (e.g. Osterbauer et al., 1996; Feipel et al., 1999; Dall’Alba et al., 2001; O¨hberg et al., 2003). In comparison to most reports on ROM in chronic neck pain, our group of patients showed substantially larger ROM. This could partly have been due to the optimization algorithm used to maximize the ROM by adjusting the coordinate system according to the preferred rotation plane of the subjects (see Methods). However, the small sample size of the present study is probably the main reason why the differences in ROM between the three groups came out as nonsigniﬁcant. The average peak velocity during cervical rotations was lower in the group of patients than in the control group (Table 2), but in contrast to in a recent study on patients with WAD (O¨hberg et al., 2003), the differences were not statistically signiﬁcant. One reason for the discrepancy might be that O¨hberg and co-workers did not adjust their velocity-data for differences in ROM (cf. Methods). Despite these differences, it seems likely that voluntary movements in fact are slower in chronic neck pain than in asymptomatic subjects. In a previous investigation, the patients of the present study demonstrated signiﬁcantly slower shoulder ﬂexions in comparison to the control group (Michaelson et al., 2003). Moreover, the insidious neck pain group executed the arm movements more slowly than the WAD group (Michaelson et al., 2003). A similar trend was indicated in the present study (Table 2). Slow movements with low

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active ROM might indicate motor control strategies developed to avoid pain and/or to maintain cervical stability through increased degree of co-activation of neck muscles (cf. Lund et al., 1991; Vlaeyen and Linton, 2000). However, since neither EMG nor psychological distress was evaluated in the present study this suggestion has to be elucidated in further investigations. 4.3. Repositioning acuity and smoothness of movement Jerk index and ROM-Variability represent novel parameters in attempts to quantify motor control disturbances in patients with chronic neck pain. The ﬁndings that both parameters were signiﬁcantly larger among patients than among asymptomatic subjects strengthen previous ﬁndings indicating movement irregularities in chronic neck pain (Osterbauer et al., 1996; Feipel et al., 1999; Kristjansson et al., 2004). Since large ROM-Variability, in similarity with large repositioning error, reﬂects variability of the end position of the rotation, it seems likely that disturbed position sense acuity is involved in both increased VE and ROMVariability (see below). The mechanisms responsible for increased jerk index remain to be clariﬁed, but unconscious motor control mechanisms rather than psychological processes might be responsible. Increased extent of co-activation of neck muscles could generate jerkier movements, as could biomechanical disturbances due to skeletal or soft tissue injuries. Finally, jerky and slow movements might be a reﬂection of motor control strategies dominated by feedback control, perhaps as a consequence of reduced acuity of the proprioceptive input, and continuous feedback corrections, or as a result of disturbed feedforward control mechanisms. The observation of larger repositioning errors in patients with chronic neck pain than among asymptomatic subjects is in agreement with previous ﬁndings (Revel et al., 1991; Kristjansson et al., 2003; Treleaven et al., 2003). In the present study, reduced repositioning acuity was shown by signiﬁcantly larger VE (Table 3). These effects were more pronounced for patients with WAD than for those with insidious neck pain. No systematic over- or underestimation (i.e. CE) of the matched target position was evident among the patients. These ﬁndings suggest that the increased repositioning errors observed in chronic neck pain are a result of poor position sense acuity due to disturbed proprioceptive input, rather than of a systematic bias in the motor control systems at central levels. This interpretation is based on fundamental psychophysical data showing that the variability (i.e. VE) of the matching errors in an adjustment task reﬂects the threshold for sensory discrimination (Gescheider, 1997). It has been shown that afferent input from muscle spindles is crucial for optimal movement precision

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(e.g. Bergenheim et al., 2000; Roll et al., 2000). Without excluding other contributing factors, it has been suggested that disturbed proprioceptive input, as a result of altered input from the muscle spindles, could constitute an important pathophysiological mechanism in chronic musculoskeletal pain conditions of various origin (Johansson et al., 2003). It is known that muscle spindle afferents convey position and movement information in ensembles of afferents (Ribot-Ciscar et al., 2003) and that the information content in such ensembles is reduced when the fusimotor control of the muscle spindles is disturbed by high activity in group III and IV muscle afferents (Pedersen et al., 1998). In an animal model it was found that excitation of chemosensitive nociceptors in cervical facet joints and muscles induce reﬂex activation of fusimotor neurones which alter the static and the dynamic sensitivity of the muscle spindles (Thunberg et al., 2001). Thus, if the signal-tonoise ratio of the information transmitted in the muscle spindle afferents is reduced in response to increased noise in the fusimotor signal, it would be reﬂected in decreased proprioceptive acuity. Such disturbances of the fusimotor control could be triggered by for instance a massive activations of mechanosensitive nociceptors that may result from the soft tissue injuries occurring in a whiplash trauma, and by activation of chemosensitive joint and muscle nociceptors which is likely to occur during inﬂammation or when the blood ﬂow in the muscle is reduced (Sjo¨lander et al., 2002).

5. Conclusion It has been proposed that deﬁcits in proprioception and motor control rather than the chronic pain itself might be the cardinal factors deﬁning chronic neck pain conditions (Michaelson et al., 2003). The results of the present study strengthen this view. In spite of the fact that the sample of patients was small and that they were chronic patients, a large variability between the patients was found regarding proprioceptive and motor control disturbances, suggesting interaction of several underlying mechanisms. This might imply that the individual patient with chronic neck pain could be characterised by a unique composition of pathophysiological and accessory mechanisms. Inclusion of methods for objective and quantitative assessment of dysfunctions in clinical practice is important in order to increase the precision of diagnosis and to enable rational development of rehabilitation methods for speciﬁc dysfunctions.

Acknowledgements The authors would like to thank Stina Langendoen and Magdalena Michaelson for valuable assistance

during the data collection. The study was supported by grants from VINNOVA (Proj. No. 510240).

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ARTICLE IN PRESS

Manual Therapy 13 (2008) 132–138 www.elsevier.com/locate/math

Original Article

Rehabilitative ultrasound measurement of select trunk muscle activation during induced pain Kyle B. Kiesela,, Tim Uhlb, Frank B. Underwoodc, Arthur J. Nitzd,e a

Rehabilitation Sciences Doctoral Program, University of Kentucky, USA Department of Rehabilitation Sciences, Division of Athletic Training, University of Kentucky, USA c Department of Physical Therapy, University of Evansville, USA d Department of Rehabilitation Sciences, Division of Physical Therapy, University of Kentucky, USA e Department of Rehabilitation Sciences, Rehabilitation Sciences Doctoral Program, University of Kentucky College of Health Sciences, 900 South Limestone, CHS 126, Lexington, KY 40536-0200, USA b

Received 16 February 2006; received in revised form 11 September 2006; accepted 9 October 2006

Abstract Rehabilitative ultrasound imaging (RUSI) is considered a valid method to measure muscle activation in key spinal muscles in asymptomatic subjects. Research measuring muscle activation with RUSI in painful subjects is limited. The aim of this study was to determine if changes in muscle activation from experimentally induced pain can be measured by RUSI. Six male subjects performed tasks known to activate the transverse abdominis (TrA) and lumbar multiﬁdus (LM) while RUSI measurements of muscle thickness were obtained during control and hypertonic saline conditions. The abdominal draw-in maneuver was used to volitionally activate the TrA and a series of upper extremity lifting tasks were used to automatically activate the LM. Pain was induced by injecting 5% hypertonic saline into the longissimus muscle adjacent to the LM at the L4 level. The percent change in muscle thickness from rest to contraction represented muscle activation. Activation was signiﬁcantly less (po0.01) during the painful condition on 4 of the 5 tasks performed for the LM and on the task performed for the TrA. These results indicate that RUSI can be used to measure pain-related changes in deep trunk muscle activation. Future research should include a larger sample size and women. r 2006 Elsevier Ltd. All rights reserved. Keywords: Rehabilitative ultrasound imaging; Transverse abdominis; Lumbar multiﬁdus

1. Introduction Contemporary rehabilitation for patients with low back pain (LBP) includes speciﬁc exercise aimed at restoring motor control of key stabilizing muscles including the transverse abdominis (TrA) and the lumbar multiﬁdus (LM) (O’Sullivan et al., 1997; Richardson and Jull, 2000; Hides et al., 2001; Moseley, 2002; Niemisto et al., 2003). Surface electromyography Corresponding author. Department of Physical Therapy, University of Evansville, Evansville, IN 47714, USA. Tel.: +1 812 479 2646; fax: +1 812 479 2717. E-mail address: [email protected] (K.B. Kiesel).

1356-689X/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2006.10.003

does not accurately measure activation characteristics of these deep spinal muscles (McGill et al., 1996; Stokes et al., 2003), requiring invasive techniques for measurement which are not routinely used in the clinical setting (Teyhen et al., 2005). Rehabilitative ultrasound imaging (RUSI) can be used to assess muscle activation by measuring change in muscle geometry during contraction. The most common measurement utilized to assess muscle activation is change in muscle thickness (Hodges, 2005). Muscle thickness change has been shown to represent muscle activation by simultaneous EMG recording in the TrA muscle (Hodges et al., 2003b; McMeeken et al., 2004) and the LM muscle (Kiesel et al., 2006) in normal subjects.

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Few studies have been conducted to measure muscle thickness change with RUSI in LBP subjects. Ferreira et al. (2004) demonstrated thickness change of the TrA is less in asymptomatic subjects with a history of LBP. This study utilized a loaded lower extremity task, similar to recumbent biking, to measured automatic recruitment of TrA over the course of the task. Critchley and Coutts (2002) used RUSI to measure thickness change in the TrA on chronic LBP subjects performing the abdominal draw-in maneuver. The magnitude of thickness change in the LBP subjects was signiﬁcantly less than asymptomatic age matched control subjects. Thickness change of the LM has not been measured with RUSI in the LBP population. RUSI has been used as biofeedback during intervention in an acute LBP population where thickness change was thought to represent activation (Hides et al., 1996). Many researchers have reported changes in muscle activation in LBP subjects as compared to asymptomatic control subjects (van Dieen et al., 2003). The majority of studies have utilized surface EMG to assess the response to pain in superﬁcial muscles. Results vary widely and are in part dependent on the task studied, with some demonstrating hyperactivity while other studies demonstrating hypoactivity in the presence of pain. These results have been used to support and refute the two main theories of how pain affects motor control: (1) pain-spasm-pain model (predicts pain increases activity) and (2) the pain-adaptive model (predicts pain will cause an increase in muscle activity when the muscles act as antagonist and decreases activity when the muscle is active as an agonist). van Dieen et al. (2003) concluded that ‘‘lumbar erector spinae EMG activity in LBP subjects is highly variable and thought to depend upon the task studied.’’ Researchers demonstrating the effects of induced pain on trunk muscle activation also offer no consistent ﬁndings, with results appearing to vary depending on the task. Arendt-Nielsen et al. (1996) induced pain with hypertonic saline and demonstrated an increase in erector spinae activity during walking. Zedka et al. (1999) measured erector spinae activity during trunk ﬂexion and extension before and after hypertonic salineinduced pain and found an increase in activity when EMG activity is normally silent and a decrease or no change when EMG activity is normally high. More recent work has focused on deep muscle activation, in particular on the timing of activation in the presence of pain. Delays in activation of the TrA, in response to rapid limb movement, have consistently been demonstrated in subjects with LBP (Hodges and Richardson, 1996), subjects with a history of LBP in remission at the time of testing (Hodges and Richardson, 1998, 1999) and in asymptomatic subjects when pain is experimentally induced (Hodges et al., 2003a). There are several studies demonstrating various impair-

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ments of the LM in subject with LBP including selective morphologic changes such as decreased girth and fatty inﬁltrate development (Hides et al., 1994, 1996; Danneels et al., 2000; Kader et al., 2000; Yoshihara et al., 2003). Despite these consistent ﬁndings, muscle activation deﬁcits of the LM have not been consistently identiﬁed. Hodges et al. (2003a) failed to show recruitment differences in the deep portions of the LM in response to rapid limb movements during induced pain. Other studies have shown diminished EMG activity in the LM during forward and backward bending (Sihvonen et al., 1997) and a reduction in fatigue resistance (Roy et al., 1989). Measurement of changes in muscle activation associated with LBP may be beneﬁcial to the clinician in development of select intervention to reverse the identiﬁed impairment. Experimental pain can be induced by many methods, but hypertonic saline-induced pain has been used extensively to test the effects of pain on various aspects of motor control (Graven-Nielsen et al., 2000) and utilized speciﬁcally to study the effects of pain on motor control of spinal muscles (Arendt-Nielsen et al., 1996; Zedka et al., 1999; Hodges et al., 2003a). Intramuscular injection of hypertonic saline is thought to produce pain by primarily exciting nociceptive ﬁbers. Other possible contributors to the pain response are increases in intramuscular pressure and a nonspeciﬁc excitation of non-nociceptive afferents (Graven-Nielsen et al., 2000), but it has been shown that injection of isotonic saline does not produce pain beyond that associated with the injection itself (Hodges et al., 2003a). Using intramuscular injection of hypertonic saline to produce pain is considered safe, reliable and comparable to clinical pain (Graven-Nielsen et al., 2000). The advantage of using experimental pain applied to healthy subjects over patients in clinical studies is the control obtained for pain intensities and duration. Such control may be important when measuring the LM because of its tendency to become inhibited quickly in those with acute LBP (Hides et al., 1996) and because of known morphological changes in chronic LBP subjects (Kader et al., 2000; Yoshihara et al., 2001, 2003) which may affect measurement accuracy. To our knowledge, no study has demonstrated if RUSI can detect change in muscle activation in those with acute pain at the time of testing. Therefore, the aim of this study was to determine if changes in muscle activation from experimentally induced pain can be measured with RUSI.

2. Methods 2.1. Subjects A convenience sample of 7 healthy male subjects (mean age ¼ 26.0 years SD 7.3, mean height ¼ 176.9 cm

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SD 10.7, mean weight ¼ 83.0 kg SD 11.7) volunteered for this study. Females were not included because of known differences in LM activation levels (Arokoski et al., 2001). Potential subjects were also excluded if they had a history of LBP or hip pain, spondylolithesis, or a congenital lumbar/sacral condition such as spina biﬁda. All volunteering subjects signed an institutional-reviewboard-approved consent form following verbal instructions of the procedure. 2.2. Procedures 2.2.1. Ultrasound measurements Rest and activation measures (control and hypertonic saline conditions) of thickness of the TrA and LM were obtained using the Sonosite 180 Plus sonography unit (Sonosite Inc, Bothell, WA, USA) with a 70 mm 2–5 MHz curvilinear transducer. The TrA measurements as described by Richardson et al. were taken with the subjects in the supine hook lying position with the transducer placed just superior to the iliac crest along the axillary line (Richardson et al., 2004). To ensure measurements were taken at similar points along the TrA, the transducer was adjusted until the medial most portion of the TrA was visualized in the far left portion of the screen (Henry and Westervelt, 2005) (Fig. 1). Subjects were then taught to preferentially activate their TrA by performing the abdominal draw-in maneuver with visual feedback from the ultrasound.

Once the skill had been adequately learned (isolated TrA activation as determined by the tester viewing the RUSI) the resting measure was captured at the end of quiet expiration followed by the activation measure. The LM measurements were taken with the subjects positioned prone on a standard plinth. An inclinometer was placed longitudinally over the lumbo/sacral junction and pillows were used to ﬂatten the lumbar curve to less than 101. The L4 spinous process was identiﬁed by palpation and marked for reference. Then the transducer was placed longitudinally along the spine, moved laterally, and then angled slightly medial until the L4/5 facet joint could be identiﬁed. This scan point was directly over the LM. A measurement from this landmark to the plane between the muscle and subcutaneous tissue was used for the thickness measurement of LM at rest and during activation (Fig. 2) (Stokes et al., 2005). To activate the LM, 2 trials each of 5 increasingly demanding contralateral upper extremity lifting tasks were performed while ultrasound images were obtained. The ﬁrst level had resistance of only the limb with the shoulder adducted and the elbow fully ﬂexed; next the shoulder was abducted to 1201 and lifted with just resistance from the limb, then graded resistance was added for the next 3 lifts based on the subject’s body weight (see Table 1). The average of the two trials for each task was used for analysis. A percent change from rest was calculated [(activityrest)/rest*100] for muscle thickness measures obtained during each task. This

Fig. 1. Sonogram of the anterior abdominal wall demonstrating measurement of the TrA at rest (left panel) and during volitional abdominal draw-in (right panel).

Fig. 2. Sonogram of a parasagital view of lumbar spine with the L4/5 facet joint in the center. Measurement of the LM at rest (left panel) and during automatic recruitment (right panel) via contralateral arm lifting while in prone position.

ARTICLE IN PRESS K.B. Kiesel et al. / Manual Therapy 13 (2008) 132–138 Table 1 Graded resistance levels for upper extremity lifting tasks in kilograms Subject mass (kg)

Level 1 UE in add. with elbow ﬂexed

Level 2 UE Level only at 1201 of 3 abd.

Level 4

Level 5

o68.2 68.2–79.5 79.5–90.9 490.9

— — — —

— — — —

0.68 0.68 0.90 0.90

0.90 1.14 1.14 1.36

0.45 0.45 0.45 0.45

percent change in muscle thickness represented muscle activation as measured by RUSI. Resting and all TrA measurements were performed with the on-screen calipers. The intratester reliability of these measures was established in a pilot study (TrA ICC3,1 ¼ 0.95, LM ICC3,1 ¼ 0.85) performed on 8 asymptomatic subjects. LM images captured during the UE lifting tasks were saved and printed for off screen manual measurement. The intraimage reliability of this measurement is (ICC3,1 ¼ 0.95). The off screen LM activation measurements were taken by a researcher who was blind to both task and condition. 2.2.2. Induced pain After completion of the measurements during the control condition, subjects remained positioned on the plinth. To induce acute pain, a 1.5 ml bolus of hypertonic saline (5%) was injected into the longissimus muscle 6 cm lateral to the L4 spinous process at a depth of approximately 3.5 cm as described by Hodges et al. (2003a). Pain was measured on a 0–10 point visual analog scale at 60 s post injection and every 60 s thereafter. Reported pain scores had to reach X4/10 and maintain that level throughout the hypertonic condition data collection. If reported pain dropped below the pre-determined threshold of 4/10, an additional 0.5 ml bolus was administered. Subjects were offered a 0.5 ml subcutaneous injection of 1% lidocaine to diminish the superﬁcial pain associated with the subsequent saline injection. 2.3. Statistical analysis Paired t-tests were used to determine if muscle activation was different between the two conditions on each of the 5 activation tasks for the LM and on the volitional TrA contraction. The alpha level was set at p0.05 and a Bonferroni correction was performed on the LM data to diminish the risk of committing a Type I error due to multiple comparisons. The correction was done by dividing the alpha level of 0.05 by the number of comparisons which was ﬁve. Therefore, the alpha level for acceptance for the LM was p0.01 and remained at p0.05 for the TrA.

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3. Results Of the seven subjects enrolled in the study, one did not reach the required pain threshold, therefore six subjects completed all aspects of the study. The results of the paired t-test indicate there was a signiﬁcant difference (pp0.01) in LM muscle activation between the control and hypertonic saline conditions for all but the second activation task (see Fig. 3). There was also a signiﬁcant difference for the TrA between conditions (pp0.01) (see Fig. 4). Table 2 includes mean and SD values in centimeters for all measurements.

4. Discussion The results of the present study indicate that induced pain attenuates the thickness change of the LM muscle during an automatic recruitment task and the TrA muscle during a volitional recruitment task. Research to establish the relationship between muscle thickness change and muscle performance measures such as EMG has been conducted on a variety of muscles including the TrA (Hodges et al., 2003b; McMeeken et al., 2004) and LM (Kiesel et al., 2006). Hodges et al. (2003b) reported a curvilinear relationship where maximum muscle thickness is reached at approximately 20% of MVIC. McMeeken et al. (2004) demonstrated a more linear relationship where thickness change can be observed up to 80% of MVIC. Thickness change in the TrA is considered a valid measure of muscle activation although the linearity of the relationship is controversial (Teyhen et al., 2005). Little research has been conducted on thickness change of the LM. In previous work, we demonstrated a linear relationship (r ¼ 0.79 po0.001) between LM thickness change and EMG activity across a narrow span of activation levels (19–34% of MVIC) (Kiesel et al., 2006). One study (Watanabe et al., 2004) utilized RUSI to evaluate thickness change in the lumbar erector spinae. The scan point for this study was lateral to the point used in the current study, over the transverse process, measuring thickness of the erector spinae group as a whole. This study did not include EMG, but did report intra and interrater reliability of the muscle thickness measurement (RX0.90) and signiﬁcant differences in muscle thickness between sitting ﬂexion, neutral, and extended spinal positions across all lumbar levels. The importance of LM function in LBP has been established (Hides et al., 1994, 2001; Kader et al., 2000; Danneels et al., 2001; Yoshihara et al., 2003), and several authors discuss the use of RUSI to measure activation and provide feedback for select training of the deep portion of the LM (Hides et al., 2001; Kermode, 2004; Lee, 2004). Although researchers have

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LM T hickness Change

40

*

% Change from Rest (mean ± SE)

35 30

∗

25

∗

∗

20 15 10

∗ Control Hypertonic Saline

5 0

1

2

3

4

5

Lifting Task

Fig. 3. Lumbar multiﬁdus thickness change expressed as a % change from rest. The X-axis represents each of 5 prone UE lifting tasks with increasing levels of load. * Indicates thickness change during the painful condition when signiﬁcantly different from non-pain condition (po0.01).

Fig. 4. Transverse abdominis thickness change expressed as a % change from rest during the volitional abdominal draw-in activity. * Indicates thickness change during the painful condition when signiﬁcantly different from non-pain condition (po0.01).

Table 2 Mean and SD of muscle thickness (cm) during control and hypertonic conditions Control

Rest Draw-in UE Lift 1 UE Lift 2 UE Lift 3 UE Lift 4 UE Lift 5

Hypertonic saline

TrA

LM

TrA

LM

D

0.4670.07 0.6870.08 — — — — —

3.2770.04 — 3.7070.57 4.0270.60 4.1770.57 4.2570.63 4.3370.66

— 0.5970.07 — — — — —

— — 3.4470.49 3.7270.63 3.8770.54 3.9370.47 4.0470.54

— 0.09 0.26 0.30 0.30 0.32 0.29

The dash indicates no data was collected by study design.

demonstrated a structural (Macintosh and Bogduk, 1986) and functional (Moseley et al., 2002) differentiation between the deep and superﬁcial ﬁbers of the LM, the anatomical differentiation between the ﬁbers is difﬁcult to identify with RUSI and we did not attempt this. The measurement we utilized, directly over the facet joint, is thought to encompass the entire LM and the contralateral UE lifting task is likely to activate the paraspinal muscles en mass. Therefore, our measurement included both the deep and superﬁcial portions of the LM. Reﬁnement of select deep LM measurement and training with RUSI requires further research. Our ﬁndings are consistent with previous studies which have demonstrated reduced thickness change in the TrA as measured by ultrasound imaging in those with chronic LBP. Critchley and Coutts (2002) reported a mean thickness change of 15% in chronic LBP subjects (duration of symptoms 54.1 months) compared to a 50% change in pain-free controls during volitional muscle activation. Ferreira et al. (2004) also demonstrated a signiﬁcant difference in thickness change of the TrA between controls and subjects with a history of LBP during an automatic recruitment task of a loaded recumbent biking-type activity. In contrast, Teyhen et al. (2005) found LBP subjects (duration of symptoms 3.3 months) were able to volitionally activate the TrA as measured by RUSI demonstrating a mean 109% thickness change from rest to activation. Substantial differences between studies may be due to differences in resting measures. Critchley and Coutts reported a mean resting thickness of 0.51 cm while Teyhen et al. reported a mean resting thickness of .21 cm. Mean thickness values during volitional activation were reported at 0.67 and .44 cm, respectively. Our data are similar to Critchley and Coutts as we both report approximately a 50% change in TrA thickness in pain-free subjects. Neither study reported pain levels at the time of testing and there was a substantial difference in duration of symptoms. We are aware of no study that has measured thickness change of the LM in LBP subjects. Hides et al. (1996) reported signiﬁcant differences in cross-sectional area of the LM, at the spinal level of pain, in those with ﬁrst time acute LBP. These subjects were then randomized to either the control group which received standard medical care of medication and education or the intervention group which added motor control exercise. This exercise protocol utilized RUSI for feedback to the subjects as they learned to volitionally activation both the TrA and LM. Thickness change of the LM was used as feedback for activation, but no thickness measurements were reported. A single case-study reported a 64% contralateral difference in LM thickness change, as measured by RUSI, with the painful side changing less than the non-painful side. Following exercise intervention, the activation difference was reported to be resolved and the patient remained symptoms-free 12

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months following intervention (Kiesel and Malone, 2004). Previous research demonstrates experimentally induced pain alters muscle activity, including delays in the timing of TrA activation (Hodges et al., 2003a) and either an increase or decrease in erector spinae activity dependent upon the phase of the movement task tested (Zedka et al., 1999). The pain-adaptation model (Lund et al., 1991) predicts pain will alter muscle activity depending on a given muscle’s role as an agonist or antagonist to control movement for protection. This model is described by Graven-Nielsen et al. (2000) in a review article as the current best explanation of how pain likely alters motor control. It is difﬁcult to categorize the role of LM in the prone UE lifting task used in this study as either agonistic or antagonistic, but the pain-adaptation model predicts increased activity when a muscle would normally be silent and decreased activity when a muscle would normally be active, therefore a decrease in LM activity could be expected. Hodges et al. (2003a) reported an initial increase in deep LM EMG amplitude following saline injection during rapid arm lifting. Differences may be related to the position of subjects. The authors postulate that because subjects were in the standing position, an initial increase in activity of the LM may have been part of a protective trunk splinting response. Limitations of this study include the small sample size as well as the lack of EMG data. Measuring if EMG also changes during the painful condition would add validity to the study as well as to the use of thickness change as a measure of muscle activation. Additionally, the strength of contraction was not measurable and maximal contraction could not be conﬁrmed in either muscle tested. This may not be relevant from a clinical perspective as high force contractions are not functional in that the stabilizing role of deep muscles is thought to occur at relatively low forces. 5. Conclusion The results of this study provide preliminary data indicating RUSI can be used to measure pain-related changes in select trunk muscle activation. This adds to the validity of using RUSI in the clinical setting and may help to expand its use beyond that of feedback and measurement for the TrA. Additionally, the decreased activation as measured by RUSI supports the pain model described by previous authors Lund and Graves-Nielsen. Acknowledgments The authors would like to thank Daniel Underwood and Joshua McCormack for their assistance with this research.

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References Arendt-Nielsen L, Graven-Nielsen T, Svarrer H, et al. The inﬂuence of low back pain on muscle activity and coordination during gait: a clinical and experimental study. Pain 1996;64(2):231–40. Arokoski JP, Valta T, Airaksinen O, et al. Back and abdominal muscle function during stabilization exercises. Archives of Physical Medicine and Rehabilitation 2001;82(8):1089–98. Critchley D, Coutts F. Abdominal muscle function in chronic low back pain patients; measurement with real-time ultrasound scanning. Physiotherapy 2002;88(6):322–32. Danneels LA, Vanderstraeten GG, Cambier DC, et al. CT imaging of trunk muscles in chronic low back pain patients and healthy control subjects. European Spine Journal 2000;9(4):266–72. Danneels LA, Vanderstraeten GG, Cambier DC, et al. Effects of three different training modalities on the cross sectional area of the lumbar multiﬁdus muscle in patients with chronic low back pain. British Journal of Sports Medicine 2001;35(3):186–91. Ferreira PH, Ferreira ML, Hodges PW. Changes in recruitment of the abdominal muscles in people with low back pain: ultrasound measurement of muscle activity. Spine 2004;29(22):2560–6. Graven-Nielsen T, Svensson P, Arendt-Nielsen L. Effect of muscle pain on motor control: a human experimental approach. Advances in Physiotherapy 2000;2:26–38. Henry SM, Westervelt KC. The use of real-time ultrasound feedback in teaching abdominal hollowing exercises to healthy subjects. Journal of Orthopaedic & Sports Physical Therapy 2005;35(6): 338–45. Hides JA, Stokes MJ, Saide M, et al. Evidence of lumbar multiﬁdus muscle wasting ipsilateral to symptoms in patients with acute/ subacute low back pain. Spine 1994;19(2):165–72. Hides JA, Richardson CA, Jull GA. Multiﬁdus muscle recovery is not automatic after resolution of acute, ﬁrst-episode low back pain. Spine 1996;21(23):2763–9. Hides JA, Jull GA, Richardson CA. Long-term effects of speciﬁc stabilizing exercises for ﬁrst-episode low back pain. Spine 2001; 26(11):E243–8. Hodges P. Ultrasound imaging in rehabilitation: just a fad? Journal of Orthopaedic & Sports Physical Therapy 2005;35(6):333–7. Hodges PW, Richardson CA. Inefﬁcient muscular stabilization of the lumbar spine associated with low back pain. A motor control evaluation of transversus abdominis. Spine 1996;21(22): 2640–50. Hodges PW, Richardson CA. Delayed postural contraction of transversus abdominis in low back pain associated with movement of the lower limb. Journal of Spinal Disorders 1998;11(1):46–56. Hodges PW, Richardson CA. Altered trunk muscle recruitment in people with low back pain with upper limb movement at different speeds. Archives of Physical Medicine and Rehabilitation 1999; 80(9):1005–12. Hodges PW, Moseley GL, Gabrielsson A, et al. Experimental muscle pain changes feed forward postural responses of the trunk muscles. Experimental Brain Research 2003a;151(2):262–71. Hodges PW, Pengel LH, Herbert RD, et al. Measurement of muscle contraction with ultrasound imaging. Muscle & Nerve 2003b;27(6): 682–92. Kader DF, Wardlaw D, Smith FW. Correlation between the MRI changes in the lumbar multiﬁdus muscles and leg pain. Clinical Radiology 2000;55(2):145–9. Kermode F. Beneﬁts of utilzing real-time ultrasound imaging in the rehabilitation of the lumbar spine stabilising muscles following low back injury in the elite athlete; a single case study. Physical Therapy in Sport 2004;5:13–6. Kiesel KB, Malone TR. Use of ultrasound imaging to measure muscular impairment and guide intervention of a patient with recurring low back pain (Poster Presentation). In American

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Manual Therapy 13 (2008) 139–147 www.elsevier.com/locate/math

Original article

The inﬂuence of a postgraduate clinical master’s qualiﬁcation in manual therapy on the careers of physiotherapists in the United Kingdom Ann Green, Jo Perry, Karen Harrison Department of Physiotherapy and Dietetics, Faculty of Health and Life Sciences, Coventry University, Priory Street, Coventry CV1 5FB, UK Accepted 30 November 2006

Abstract Over the last decade there has been potential for manual therapists to extend their roles and develop their careers. In order to explore the career pathways of a group of postgraduate manual therapists and to identify the inﬂuence of Master’s education on those careers, a postal questionnaire was sent to all graduates from a clinically based programme (response rate 62.3%, n ¼ 48, with representation from each year over a 10-year period). All the respondents were still working in physiotherapy and the majority had a clinical element to their role (83%). The new career framework, which seeks to enable therapists to progress their careers and retain a clinical work load is demonstrated within this sample, with 6.2% achieving Consultant Therapist roles, 14.4% in Extended Scope Practitioner posts and 16.6% working as Clinical Specialists. Positive contributions from Master’s education were the status of the qualiﬁcation, improved clinical skills and increased conﬁdence. Negative factors were less clinical ‘hands-on’ within their roles, lack of time and an increase in management responsibilities. Findings suggest that Master’s education has enabled the participants to take on the new roles that have resulted from a raft of political imperatives but further work could explore the issues around positive and negative drivers. r 2007 Elsevier Ltd. All rights reserved. Keywords: Manual therapy; Physiotherapy careers; Postgraduate education

1. Introduction In the United Kingdom (UK) the potential role that a manual therapist may undertake has expanded dramatically over the past decade. This has arisen primarily as a result of a number of politically driven imperatives. The NHS Plan (2000) has acknowledged the role of Allied Health Professionals (AHPs) and has given a commitment to ‘expanding the roles which allied health professions play in health and social care, ensuring they can use their skills ﬂexibly and creatively to the beneﬁt Corresponding author. Tel.: +44 2476 888554; fax: +44 2476 888020. E-mail address: [email protected] (A. Green).

1356-689X/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2006.12.001

of patients’ (DoH, 2000). Within the NHS there was a subsequent commitment to developing AHP consultant posts, with a target of 250 AHP consultants in England and Wales by 2004. The Advanced Letter (DoH, 2001), with arrangements for consultant posts, stated that consultants would be experts in their clinical ﬁeld and irrespective of the particular ﬁeld or profession would have four core functions:

Expert practice. Professional leadership and consultancy. Education, training and development. Practice and service development, research and evaluation.

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The Advanced Letter (DoH, 2001) also indicated that there would be individuals who had already taken on extended roles or who were delivering specialist clinical services that operate below the consultant level. Extended Scope Practitioners (ESPs) are deﬁned as those who have ‘extended physiotherapy practice to encompass tasks that may previously have been undertaken by the medical profession’ (CSP, 2005a). The ﬁrst UK physiotherapy ESP role recorded in the literature was in 1989 and their role was as ‘a ﬁrst in-line ﬁlter system for those patients who may not require surgical intervention’ (Byles and Ling, 1989). Since then, the number of ESP appointments has grown, with the extended scope interest group reporting a membership of 400 (CSP, 2005a). Clinical specialists ‘work within a particular ﬁeld and their practice falls within the scope of practice of physiotherapy’ (CSP, 2001) with the roles having core elements of:

Clinical expertise. Clinical teaching. Evaluation. Practice and/or service development.

The acquisition of a Master’s degree is considered essential to attain these new therapy posts. Craik and McKay (2003) and the Chartered Society of Physiotherapy (CSP, 2002) indicate that to engage in the educational and professional development supporting function, Consultant Therapist post-holders will be working to a Master’s level or beyond. During the last decade, within the UK there has been a huge growth in taught postgraduate study, with a 106% increase in Subjects Allied to Medicine between 1996/1997 and 2001/2002 (Sastry, 2004). In 1992, at Coventry University, the MSc Manipulative Therapy programme was developed. It was the ﬁrst of its kind in the UK and was developed in partnership with the clinical interest group, the Manipulative Association of Chartered Physiotherapists (MACP). In the UK, the MACP is the specialist manipulative therapy group recognised by the International Federation of Orthopaedic Manual Therapists (IFOMT). The IFOMT (2005) vision is ‘promotion of excellence and unity in clinical and academic standards for manual/musculoskeletal physiotherapists’. The MACP has a history of providing formal education and continuing professional development for manual therapists, and recognised the need to offer Master’s level study in a taught MSc. The MACP accredited the Coventry University programme, and students become eligible for MACP membership once they successfully complete the postgraduate diploma stage of the course. In the UK, there are now 13 Master’s programmes, accredited by the MACP that are based around manipulative therapy, musculoskeletal

physiotherapy or neuromusculoskeletal physiotherapy (MACP, 2005). The Quality Assurance Agency (QAA) for Higher Education (2001) states that post-graduate students studying at Master’s level ‘will have shown originality in the application of knowledge, and they will understand how the boundaries of knowledge are advanced by research. They will be able to deal with complex issues both systematically and creatively, and they will show originality in tackling and solving problems’. For AHPs Master’s level education offers opportunities to explore practice and develop knowledge and clinical reasoning skills (Alsop and Lloyd, 2002) and according to the QAA (2001) Master’s level students will have the ‘qualities needed for employment in circumstances requiring sound judgement, personal responsibility and initiative, in complex and unpredictable professional environments’. The graduates from the Coventry University MSc Manipulative Therapy programme should, therefore, be ideally placed to fulﬁl the new roles within the NHS as they have attained a recognised Master’s level qualiﬁcation from a programme that aims to ‘enable the development of senior practitioners into specialist roles within clinical practice, research and educational environments’ (Coventry University, 2001). 1.1. Purpose The aim of this study was to explore the career pathways of these graduates and the inﬂuence of Master’s education on their careers. With new ways of working within the NHS and opportunities for consultant, extended and specialist roles, the study set out to establish where these graduates are now working and in what roles, and how Master’s education had inﬂuenced these positions.

2. Methods A retrospective study of postgraduate physiotherapists was designed to explore their career development and the inﬂuence of Master’s education on their current roles. The two-part study was questionnaire based and allowed for information and views of a large number of participants to be collected. Graduates from the MSc Manipulative Therapy programmes from 1994 to 2005 were invited to complete the postal questionnaire. Questionnaires were sent to all of the students who had completed the programme at either the postgraduate diploma stage (when eligibility for MACP membership is achieved) or at graduation with the award of a full Master’s degree. Coventry University Ethics Committee granted ethical approval and permission was gained from the MACP to utilise their membership

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database to cross-reference current locations of participants. An information sheet was sent to all potential participants with the questionnaire. Informed consent was assumed if a questionnaire was returned. An independent research assistant coded responses and all respondents were assured anonymity and conﬁdentiality. The questionnaire was followed and complemented by the use of group interviews utilising focus group technique, whereby the largely factual ﬁndings from the questionnaire were explored in greater depth with the participants.

2005 2004 Year of Graduation from MSc

141

2003 2002 2001 2000 1999 1998 1997 1996

2.1. The questionnaire

1995 1994 0

2

4

6 Count

8

10

12

Fig. 1. The distribution of respondents according to year of graduation.

The questionnaire was piloted by three former graduates; a clinician, a researcher and a lecturer. Minor changes were made to the ﬁnal questionnaire mostly to enhance clarity. The ﬁrst section of the questionnaire asked about the participant’s current role and career pathway in chronological order since their initial physiotherapy

25

20.83%

20 18.75%

16.67%

15 Percent

14.58%

10

6.25%

6.25%

5

6.25%

4.17%

2.08%

0

Consultant Clinical Therapist Specialist

ESP

2.08%

2.08%

Clinical Super- Senior I Senior II Private Lecturer combined combined Team intendent Practice private private Lead Physiopractice &practice & therapist sport lecturer Current role

Fig. 2. Current roles of respondents.

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142

quency of response by two researchers independently after which consensus was reached.

qualiﬁcation. The year of graduation from the Postgraduate Diploma/MSc was also identiﬁed. The second section explored Master’s education and its inﬂuence on their career. This section included: openended questions on how the MSc contributed to their current roles and about the people or factors that inﬂuenced or hindered the development of Master’s education, key aspects of their role that had changed because of the Master’s qualiﬁcation and career aspirations.

3. Findings The response rate from the 77 postgraduates who were contacted was 62.3% (n ¼ 48) and were representative of all years from 1994 to 2005 (Fig. 1). 3.1. Current roles of participants

2.2. Analysis

Fig. 2 shows that the participants were in a range of roles ranging from consultant therapists to senior IIs and within a range of clinical settings including, the NHS, private practice and higher education. Fig. 3 illustrates that the majority of participants’ roles are in clinical practice (83%), with 14.5% within education and 2% in research. The time taken from undergraduate education to completing the MSc programme was a mean of 10.48

Quantitative data from the questionnaires was entered into the Social Package for Social Scientists (SPSS Version 12) in order to undertake descriptive analysis. Content analysis was conducted for the responses in the second part of the questionnaire. The responses from the open-ended questions were identiﬁed, with categories developed and quantiﬁed in terms of fre-

50

47.92%

Percent

40

30

20 14.58%

14.58%

10

8.33% 6.25% 2.08%

0

Clinical

Research

2.08%

Education

2.08%

2.08%

combined combined combined combined combined all categories clinical & clinical & clinical & clinical, clinical, research educational managerial research & managerial & educational educational Major part of role

Fig. 3. Major components of participants’ roles.

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years. Fig. 4 shows the time taken to achieve their current posts since MSc completion, with means of 8.7 years for the Consultants, 1 year prior to completion of the MSc for Clinical Specialists, at completion for ESPs and 2.4 years for Lecturers (Tables 1 and 2). 3.2. Career aspirations

Mean Time taken to achieve current post since MSc (in years)

The roles that participants aspired to are illustrated in Fig. 5. The key roles were Consultant Therapist (26%), Researcher (26%) and Lecturer practitioner (16%).

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4. Discussion All the respondents were still working as physiotherapists and 6.25% had achieved the role of Consultant Therapist. The Consultant Therapists from this programme represented 14% of all musculoskeletal Consultant Therapists currently in post in England and Wales (Limb, 2005). The remainder were currently engaged in a range of new roles of ESP (14.5%), Clinical Specialist (16.6%) and 18.75% have pursued an academic career. Whilst the response rate was good

10 8.67

8

6

4

2.38

2

-2

-1

-0.14

0

Consultant Therapist

ESP

Clinical Specialist Current role

Lecturer

Fig. 4. Times taken from completion of M.Sc. programme to current role (in yrs).

Table 1 Inﬂuence of the MSc on the participant’s current role: contributing factors and changes (n ¼ number of responses) Contributing factors to current role

Perceived positive changes to role

Perceived negative changes to role

Improved conﬁdence in self and conﬁdence in practice (24) Eligible for current role (23)

Involvement in teaching (14)

Less clinical ‘hands-on’ for the individual (9) More management responsibilities (5)

Updating clinical/manual skills (20)

Development of their own clinical reasoning and the ability to facilitate the clinical reasoning of others (12) Advanced clinical skills (11)

Improving clinical reasoning (15)

Ability to undertake research (9)

Greater depth of knowledge (13) Ability to evaluate research and apply evidence based practice (12) Being able to teach others (12)

Enhanced professional proﬁle (9)

Increased expectations from others of the individual (4) Lack of enhancement of pay and reward (4)

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144

30

25.81%

25.81%

25

Percent

20

15 12.9%

9.68%

10

9.68%

6.45%

5 3.23%

0

Consultant

Clinical specialist/ ESP

Professor

3.23%

Researcher

Lecturer

Lecturer Combined Owner of own practitioner ESP & Private practice practitioner

Role aspirations

Fig. 5. Career aspirations of participants.

Table 2 Factors or individuals involved in the development of Master’s education (n ¼ number of responses) Individuals or factors giving support, encouragement or motivation during the development of Masters’ education

Factors giving discouragement during the development of Masters education

Academic Tutors (21) Family members (13) Self-determination to achieve personal goals (10)

Lack of time (13) Large caseloads (10) Attitude of employers (9) Perception of ‘poor vision’ of the NHS as an organisation (9)

(Mangione, 1998), the 37.3% nonresponders may include those no longer in practice who might consider the content of the questionnaire of no interest and ‘ghosts’ described by Pope and Croft (1996) as those individuals in the sample who did not receive the questionnaire for a variety of reasons. Clinical practice formed a large part of the participants’ current roles and this supports Gosling’s (1999) ﬁndings that the majority of physiotherapists who have completed a well-established Master’s degree in the musculoskeletal ﬁeld had remained in clinical practice. Craik and McKay (2003) on commenting on the four core functions of the Consultant Therapist found that the primary focus was clinical work.

ESP and Clinical Specialist roles were usually achieved during participation in the Master’s programme, around the time of the postgraduate diploma stage with its parallel eligibility for MACP membership. MACP membership requires ‘that clinicians must complete a recognised postgraduate course of study, many of which are at Master of Science level’ (MACP, 2005). This suggests that the taught elements of the programme with a strong clinical focus, along with the MACP membership, provide the entry requirements and attributes for these roles. A number of studies have found value in experienced physiotherapists acting in an extended role related to assessment and diagnosis for musculoskeletal conditions (Daker-White et al., 1999;

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Dickens et al., 2003). As participants achieved ESP and Clinical Specialist roles before the dissertation component, it could be considered to be nonessential for these roles, though the majority of students continue to undertake the dissertation and successfully complete the total Master’s component. Participants agreed that it was the status of the qualiﬁcation that made them eligible for their new roles. Gosling (1999) stated that ‘there was a perception that those who had gained a Master’s degree already had a ‘market advantage’ over colleagues in terms of career progression, even if there were no tangible monetary rewards’. Not all specialist post holders will have a Master’s qualiﬁcation and there will be other factors that have contributed to their success. Further work to proﬁle specialist posts may reveal other important skills and attributes. There are currently 70 AHP consultant posts with 34 in physiotherapy and of those, 22 are musculoskeletal consultants (Limb, 2005). When considering the results of this study and the time between completing the MSc qualiﬁcation and achieving Consultant status, it is important to acknowledge that the ﬁrst physiotherapy Consultant Therapist post was created in 2002 and it may be that these posts will be achieved sooner now that they are available. However, progress towards the target of 250 AHP Consultant posts by 2004 is slow. Improving clinical skills was seen as an important contribution to the careers of participants. This is evident from responses that show the majority are in clinical roles. Owen (1998), cited by Gosling (1999), anticipated that as more physiotherapists gain higher qualiﬁcations and the number of Clinical Specialists and ESP posts grow there would be less of a desire for Master’s level study to form a path out of clinical practice. The results of the current study support this predicted trend and show that a career framework that acknowledges and rewards clinical expertise results in retention of physiotherapists in the NHS, with an enhanced academic proﬁle. Previous studies (Beeston et al., 1998; Gosling, 1997; Stathopoulos and Harrison, 2003) have described the acquisition of a Master’s qualiﬁcation as a potential hindrance to the maintenance of a clinical role and Master’s postgraduates have, ‘swum against the tide’ of misunderstanding relating to clinical commitment and patient/service enhancement. Postgraduates now ﬁnd they are ‘swimming with the tide’ as a Master’s education is considered essential to achieve specialist roles and, as the majority of these postgraduates have remained in clinical practice, their commitment to practice has been demonstrated. Assumptions from some clinical interest groups (Gosling, 1999) that Master’s degrees move clinicians away from clinical practice into an academic career are not borne out by the ﬁndings of this study. Participants who have remained in clinical practice are now

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beneﬁting from career structures that encourage therapists to specialise clinically. Indeed, early results of job matching and Agenda for Change (AfC) banding that have been reported by the CSP in Frontline (2005b) show that all the Consultant Therapist posts reported to date, have been banded in 8 (the highest band) and the majority of clinical specialists in Band 7 or 8a. Senior 1 physiotherapists are banded in 6 or 7. Financial reward is common to UK holders of postgraduate qualiﬁcations with a reported average of 28% premium to their salary after 6 months, compared to ﬁrst degree holders (Sastry, 2004). Positive contributions the study participants attributed to the Master’s qualiﬁcation were the enhancement of teaching, research, clinical reasoning and the advancement of clinical skills. These contributions closely follow the requirements of Consultant Therapist roles to ‘retain clinical excellence within the service’ (DoH, 2000), and satisﬁes the requirements of clinical expertise within the ESP and Clinical Specialist roles. A study by King and Bithel (1998) compared clinical reasoning in musculoskeletal physiotherapists who had received formal specialist training and were MACP members, with equally experienced physiotherapists, who had not received the formal training and were not MACP members. They found that those with specialist training were able to reason faster and solved problems with less error with enhanced self-monitoring strategies. The clinical reasoning of the specialists was at a deeper level conceptually, and they used enhanced strategies for evaluation and synthesis to determine how information presented to them ﬁtted with clinical patterns and syndromes that they had encountered previously. For postgraduate education, the function of universities is to develop analytical and critical thinkers. The QAA Qualiﬁcations Framework describes holders of a Master’s qualiﬁcation as ‘having the qualities and transferable skills necessary for employment that require decision making in complex and unpredictable situationsyand the ability to make informed judgments on complex issues in specialist ﬁelds, often in the absence of complete datay .’ Where some physiotherapists may have previously questioned the relevance of Master’s education to clinical practice, the QAA framework acknowledges and articulates Master’s level knowledge and skills as underpinning theory and practice. It is important that Master’s programmes for physiotherapists articulate these factors in the curriculum, course design and learning outcomes. Gosling (1999) has suggested that some physiotherapists were frustrated with the mechanisms of university accreditation and validation procedures because they were not designed to acknowledge and articulate ‘the high level psychomotor skills and tacit knowledge required for clinical practice’ within their procedures. The growth in MACP accredited

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programmes within the last decade suggests that this situation is being addressed, and programmes are being designed to ensure that graduates are ﬁt for award (MSc), ﬁt for practice (MACP membership), and ﬁt for purpose (to fulﬁl consultant, specialist and extended clinical roles). From the survey, the individuals who contributed to the support, encouragement and motivation of the respondents in their Master’s education and in their practice were academic tutors, family and self. Support of family and friends has been recognised as essential to successful study (Alsop and Lloyd, 2002; Conneeley, 2005) though negative effects on family relationships have also been reported (Conneeley, 2005). Many participants cited their own self-determination to succeed as a positive driver in the process. The negative themes associated with the participant’s role since achieving the Master’s qualiﬁcation focus around a reduction in clinical ‘hands-on’ work, an increase in emphasis on management and raised expectations from others. A study into the attractiveness of the NHS as an employer found that staff that chose agency and independent sector work had become increasingly frustrated by the amount of administration and teaching commitments required of senior staff in the NHS. Consequently, as their NHS careers progressed, there was a reported reduction in contact time with patients (Park et al., 2003). The independent sector was attractive because it offered greater opportunity for promotion without sacriﬁcing clinical workload. Though the majority of participants in this study still have a clinical element to their role, frustration with the increasing demands of teaching others and being a departmental source for advice and expert opinion were reported. These factors have been acknowledged by other studies (Conneeley, 2005, Stathopoulos and Harrison, 2003) as being a negative aspect of Master’s achievement. However, for those continuing within the NHS and hoping to achieve a Consultant Therapist post, the job description recognises their clinical contribution and that practice should contribute to 50% of these roles (DoH, 2000). Professional leadership, consultancy, education, training and development are also considered to be within the remit of the post, and it is understandable how frustrations may arise from acting out this complex and often diverse role. Colleagues may also have high expectations of post holders and this has been recognised by Conneeley (2005) where being viewed as experts could raise difﬁculties because ‘as soon as you say you’re doing a Master’s they have this really high expectation’. Stathopoulos and Harrison (2003) suggest that the change in an individual’s approach to practice whilst studying for or on completion of a Master’s degree, may be seen as a threat to other colleagues and can lead to frustrations.

Participants in this study cited the often unhelpful attitudes of employers and the lack of vision of the NHS as an organisation as factors that had discouraged their development. Stathopoulos and Harrison (2003) have discussed resistance to change and under-use of potential in the work place. Participants indicated that enhancement of selfconﬁdence was a major contribution to their professional and personal development as a result of studying for this Master’s degree. Stathopoulos and Harrison’s (2003) study conducted focus groups with Master’s level physiotherapists who had remained in clinical practice and the development of conﬁdence was a major theme here also. These participants reported ‘a general feeling of well being in their professional and personal lives, which should not be underestimated’ (Stathopoulos and Harrison, 2003). This conﬁdence they attributed to a sense of achievement and their increased credibility in the eyes of others. More recently, a focus group by Conneeley (2005) explored the beneﬁts of Master’s level study and found that their experience of M level was not seen exclusively in terms of their professional or personal lives but that the two had become integrated; it’s just made everything more interesting againyy I need to learn something new, I need to do something new and I feel now that I’m thinking on a completely different levely..you look at things differently. Other factors that were cited by participants in the current study were their enhanced knowledge and ability to engage in evidence based practice, enhanced clinical reasoning and their ability to evaluate research. These factors are included in the speciﬁc abilities, thinking processes and skills that the CSP expects to see in Master’s level programmes (CSP, 2003) and match with the job requirements of the new and extended roles.

5. Conclusion Participants in this study have taken opportunities offered by a career structure that acknowledges new and extending roles for AHPs and physiotherapists. Some of the early postgraduates will have encountered challenges and resistance to their developing knowledge and skills but have nevertheless been well placed to maximise the new opportunities offered in the workplace. Factors that can encourage or discourage progress have been identiﬁed and further work using focus groups methodology will explore these factors in depth. In the current climate where a new career framework is in its infancy, it is important to explore the opportunities and challenges for these postgraduates. This will enable employers and professional bodies to provide appropriate continuing professional development and adequate support

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mechanisms for such ground breaking specialists who value clinical contact.

Acknowledgements MACP for granting permission for access to their database. Centre for Higher Education Development (CHED) at Coventry University for a grant to support the research. The respondents to the questionnaire for their participation. References Alsop A, Lloyd C. The purpose and practicalities of postgraduate education. British Journal of Occupational Therapy 2002;66(6):281–3. Beeston S, Rastall M, Hoare C. Factors inﬂuencing the uptake of taught Masters programmes amongst physiotherapists. Physiotherapy 1998;84(10):480–6. Byles SE, Ling RSM. Orthopaedic out-patients: a fresh approach. Physiotherapy 1989;75:435–7. Chartered Society of Physiotherapy. Specialisms and specialists: guidance for developing the clinical specialist role. Information paper PA23. London: Chartered Society of Physiotherapy; 2001. Chartered Society of Physiotherapy. Physiotherapy consultant (NHS): role, attributes and guidance for establishing posts. PA56. London: Chartered Society of Physiotherapy; 2002. Chartered Society of Physiotherapy. Master’s level programmes within post-qualifying education: criteria and expectations. QA03. London: Chartered Society of Physiotherapy; 2003. Chartered Society of Physiotherapy. /www.csp.org.uk/director/ groupandnetworks.cfmS, 2005a. Chartered Society of Physiotherapy. Agenda for change: job matching and our 2006 pay claim. Frontline 2005b; November 2. Conneeley A. Study at Master’s level: a qualitative study exploring the experience of students. British Journal of Occupational Therapy 2005;68(3):104–9. Coventry University. Programme speciﬁcation for PG Dip/MSc Manipulative Therapy, Coventry University; 2001.

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Craik C, McKay EH. Consultant therapists: recognising and developing expertise. British Journal of Occupational Therapy 2003;66(6):281–3. Daker-White G, Carr AJ, Harvey I, Woodhead G, Bannister G, Nelson J, et al. A randomised clinical trial: shifting boundaries of doctors and physiotherapists in orthopaedic out-patient departments. Journal of Epidemiology and Community Health 1999;53:643–50. Department of Health. Meeting the challenge: a strategy for the allied health professions. London: DH; 2000. Department of Health. Arrangements for consultant posts—for staff covered by professions allied to medicine PT ‘A’ Whitley Council Advance Letter PAM (PTA) 2/2001. Leeds: DH; 2001. Dickens V, Ali F, Gent H, Rees A. Assessment and diagnosis of knee injuries: the value of an experienced physiotherapist. Physiotherapy 2003;89(7):417–22. Gosling S. Physiotherapy and postgraduate study. Physiotherapy 1997;83(9):131–5. Gosling S. Physiotherapy and postgraduate study: a follow up discussion paper. Physiotherapy 1999;88(3):117–21. International Federation of Manual Therapists. Vision statement. /www.ifomt.orgS, 2005. King CA, Bithel C. Expertise in diagnostic reasoning: a comparative study. British Journal of Therapy and Rehabilitation 1998;5(2): 78–87. Limb M. Where are the consultant posts? Frontline 2005; August 3:15. Mangione TW. Mail surveys. In: Handbook of applied social research methods. Thousand Oaks: 1998. Sage Publications; p 399–427. Manipulative Association of Chartered Physiotherapists, /www.macpweb.orgS, 2005. Owen G. Extended scope practitioners in orthopaedic out patient clinics: a growing ﬁeld in the UK. REHAB International 1998;Fall 48:33–4. Park JR, Coombs CR, Wilkinson AJ, Loan-Clarke J, Arnold J, Preston D. Attractiveness of physiotherapy in the NHS as a career choice: a qualitative study. Physiotherapy 2003;89(10):575–83. Pope D, Croft P. Surveys using general practice registers: who are the non-responders? Journal of Public Health Medicine 1996;18:6–12. Quality Assurance Agency for Higher Education. Framework for higher education qualiﬁcations in England, Wales and Northern Ireland. QAA, 2001. Sastry T. Postgraduate education in the United Kingdom. London: Higher Education Policy Institute; 2004. Stathopoulos I, Harrison K. Study at Masters level by practising physiotherapists. Physiotherapy 2003;89(3):158–69.

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Manual Therapy 13 (2008) 148–154 www.elsevier.com/locate/math

Original article

The relationship between head posture and severity and disability of patients with neck pain Chris Ho Ting Yipa, Thomas Tai Wing Chiub,, Anthony Tung Kuen Poonc a

Physiotherapy Department, Queen Mary Hospital, Hong Kong Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong c A&J Physiotherapy Clinic (Acupuncture and Manipulation), Hong Kong

b

Received 4 February 2005; received in revised form 23 August 2006; accepted 30 November 2006

Abstract Study Design: A cross-sectional correlation study. Objectives: To investigate the relationship between head posture with pain and disability in patients with neck pain. Method: Sixty-two subjects with neck pain and 52 normal subjects were recruited by convenience sampling. The forward head posture was measured via the craniovertebral (CV) angle by using the Head Posture Spinal Curvature Instrument (HPSCI). The Chinese version of Northwick Park Neck Pain Questionnaire (NPQ) and Numeric Pain Rating Scale (NPRS) were used to assess neck pain disability and severity. The difference in CV angles between the two groups and Pearson’s correlation coefﬁcient between the CV angle, NPQ and NPRS were determined. Results: There was a signiﬁcant difference in the CV angle between subjects with and without neck pain. CV angle was negatively correlated with NPQ ðrp ¼ 0:3101, p ¼ 0:015) and NPRS ðrp ¼ 0:329; p ¼ 0:009Þ. It was also negatively correlated with age ðrp ¼ 0:380; p ¼ 0:002Þ. When age was taken into account, the CV angle was negatively correlated with NPQ ðrp ¼ 0:3101; p ¼ 0:015Þ but showed no signiﬁcant correlation with NPRS ðrp ¼ 0:1848; p ¼ 0:154Þ. Conclusion: The CV angle in subjects with neck pain is signiﬁcantly smaller than that in normal subjects. There is moderate negative correlation between CV angle and neck disability. Patients with small CV angle have a greater forward head posture, and the greater the forward head posture, the greater the disability. r 2007 Elsevier Ltd. All rights reserved. Keywords: Correlation; Craniovertebral angle; Neck disability

1. Introduction Proper posture is believed to be the state of musculoskeletal balance that involves a minimal amount of stress and strain on the body. Although correct posture is desired, many people do not exhibit good posture (Haughie et al., 1995). An ideal posture is considered to exist when the external auditory meatus is aligned with the vertical postural line. The vertical posture line, as seen in a side view, passes slightly in front of the ankle joint and the centre of the knee joint, Corresponding author. Tel.: +852 27666709; fax: +852 23308656.

E-mail address: [email protected] (T.T.W. Chiu). 1356-689X/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2006.11.002

slightly behind the centre of the hip joint and through the shoulder joint and the external auditory meatus (Haughie et al., 1995). Forward head posture is one of the common types of poor head posture seen in patients with neck disorders (Haughie et al., 1995; Hickey et al., 2000; Good et al., 2001; Chiu et al., 2002). Forward head posture means that the head is in an anterior position in relation to the theoretical plumb line, which is perpendicular to a horizontal line through the centre of gravity of the body. Therapists rate the severity of the anterior positioning of the head as minimal, moderate or maximal without any objective or numeric values. A decision regarding normality or otherwise is then based on clinicians’ experience and

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perception of what constitutes a normal or ‘‘ideal’’ posture, and is therefore considered to be a potential source of error (Griegel-Morris et al., 1992). One objective method of assessing head posture is through measuring the craniovertebral (CV) angle (Watson, 1994). It is the angle between a horizontal line through the spinous process of C7 and a line from spinous process of C7 through the tragus of the ear forming the CV angle (Fig. 1). Neutral position and resting head posture are synonymous with ‘‘natural head posture’’ (Hickey et al., 2000). It is attained by asking the subject to perform large amplitude cervical ﬂexion and extension gradually decreasing to rest in the most comfortably balanced position (Watson, 1994). The CV angle appears to be a representative measurement of a combination of an anterior or posterior position of the lower cervical spine and the associated upper cervical ﬂexion or extension. It is imperative that the instrument and method chosen to assess head posture clinically are reliable, objective, easy to use and produce immediate results when assessing a patients’ condition as well as measuring the progress of the patient after therapeutic intervention (Wilmarth and Hilliard, 2002). There are many instruments to assess head posture, including the Rocabado Posture Gauge, the Cervical Range of Motion (CROM) Instrument, the plumb line and photographic imaging. However, they all have disadvantages such as a complicated procedure, an

Fig. 1. The craniovertebral (CV) angle.

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expensive cost and being inconvenient to use clinically. The Rocabado posture gauge cannot be used to measure the CV angle. It measures the horizontal distance from the tangent of the most posterior thoracic spinous process to the most anterior cervical spinous process (Willford et al., 1996). The plumb line method is simple but is limited by the subjective nature of determining forward head posture (Wilmarth and Hilliard, 2002). Therapists rate the degree of anterior translation of the head as minimal, moderate or maximal without objective and numeric values though the inter-tester reliability is moderate ðICC ¼ 0:738Þ (Wilmarth and Hilliard, 2002). The CROM instrument with an extension arm for head posture measurement is cumbersome (Garrette et al., 1993). Photographic imaging although accurate is time-consuming and does not allow immediate feedback of results (Wilmarth and Hilliard, 2002). An instrument, the Head Posture Spinal Curvature Instrument (HPSCI), designed by Wilmarth, was developed to measure both the head posture and the cervical curvature (Wilmarth and Hilliard, 2002). This HPSCI was designed to eliminate the cumbersome use of multiple instruments to provide a more efﬁcient assessment tool with immediate feedback in order to facilitate measurement in a clinical setting. The HPSCI is a noninvasive, inexpensive measurement method which has been demonstrated to produce consistent intra-rater results ðICC40:9Þ across days and trials (Wilmarth and Hilliard, 2002). There were no previous published studies that had identiﬁed an association between forward head posture and the level of neck pain severity and disability. Griegel-Morris et al. (1992) identiﬁed an increased incidence of cervical pain, inter-scapular pain and headache with forward head posture; however, they did not establish a relationship between the severity of neck pain and the degree of postural abnormalities. Willford et al. (1996) found that there was no signiﬁcant difference in the forward head posture between groups of subjects with different levels of neck pain, although they did ﬁnd that subjects wearing multifocal lenses had a greater degree of forward head posture when compared with non-multifocal lens wearers. However, the sample size was small and the validity of the pain assessment tool was questionable in their study. Szeto et al. (2002) showed that there were trends for increased head tilt and neck ﬂexion postures in the symptomatic subjects presenting with neck and shoulder discomfort when compared to the asymptomatic subjects. However, the study by Szeto et al. did not evaluate the relationship between head posture and the degree of disability caused by neck pain. Moreover, the subjects in their study were limited to female clerical staff. From our clinical experience, we hypothesize that there is a relationship between CV angle and pain and

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the disability level in patients with neck pain. Thus, the objectives of this study are to determine: 1. if there is any difference in the CV angle between subjects with and without neck pain; 2. if there is any relationship between head posture as measured by CV angle with neck pain and the disability level in patients with neck pain. The signiﬁcance of this study may give clinicians further objective information to evaluate the severity and disability of neck pain by measuring the CV angle using the HPSCI.

2. Materials and methods 2.1. Subjects There were two groups of subjects. The non-neck pain (control) group consisted of 52 subjects (mean age 42.33, SD 11:18) and the neck pain group consisted of 62 subjects (mean age 39.92, SD 10:80). Both groups were recruited from a physiotherapy out-patient department by convenience sampling. Subjects in the non-neck pain group were patients with other problems referred for physiotherapy treatment such as knee pain, sprained ankle, tennis elbow, etc. They had not suffered from neck pain in the past three years. Subjects in the neck pain group were diagnosed to have neck pain with or without referred pain, numbness or paraesthesia over the upper limbs and were referred for physiotherapy by a physician. Subjects were excluded if they had experienced, or were experiencing, one or more of the following: a history of cervical fracture or trauma, cervical surgery, idiopathic scoliosis, bone cancer, spasmodic torticollis or neurologic motion disorder, disease of the central nervous system, persistent respiratory difﬁculties over the past ﬁve years, any hearing impairment requiring the use of a hearing aid, temporomandibular surgery or dysfunction and any visual impairment not corrected by glasses. Written consent was obtained from all subjects. This study was approved by the Human Research Ethical Committee of the Hong Kong Polytechnic University.

3. Procedure 3.1. Head posture measurement (CV angle) For the head posture measurement, subjects from both groups were assessed in their ﬁrst physiotherapy session before any treatment was given. Their diagnoses were known to the principle investigator and they were recruited according to the inclusion criteria. The

subjects were asked to give consent and they were asked not to tell the assessor about their diagnoses. The measurements were taken by an experienced physiotherapist who was blinded to the grouping of the subjects. During the assessment, the subject was required to stand in a relaxed posture. The assessor ﬁrst located the spinous process of C7 by asking the subject to ﬂex and extend the neck. The C7 spinous process is more prominent, whereas the C6 spinous process is absent in palpation when the neck is extended. The C7 spinous process was then marked by a small ﬂag to ensure the correct location and consistency of the bony landmark. The subject was then instructed to ﬂex and extend his or her head three times and then rest the head in a comfortable neutral position (Watson, 1994). The assessor performed the assessment in a left sagittal view. The measurement (CV angle) was taken with the HPSCI. The assessor aligned the axis of the instrument with the C7 spinous process in the left sagittal view. The instrument was placed adjacent to the shoulder. Then, the movable arm of the instrument was aligned with the tragus of the ear and the stationary arm was aligned perpendicularly to the ﬂoor. The alignment with the ﬂoor was conﬁrmed with the line level that was attached to the stationary arm. Once it was levelled, a measurement (the angle between the movable and stationary arms) to the nearest degree was made and then recorded (Fig. 2). If the indicator fell between two whole numbers, the smaller degree would be recorded in order to be consistent. A total of three measurements were made. A 2-min rest was given to the subject between each measurement. The mean value was evaluated (Wilmarth and Hilliard, 2002).

3.2. Neck pain disability and severity After the three measurements, subjects with neck pain were required to ﬁll in the Chinese version of Northwick Park Neck Pain Questionnaire (NPQ) (Chiu et al., 2001) and Numeric Pain Rating Scale (NPRS). It was considered unlikely that the CV angle measurement protocol would affect intensity of pain symptoms. The NPQ has been found to be reliable and valid for patients with neck pain (Chiu et al., 2001); it consists of nine ﬁve-part questions that assess the subject’s symptoms, from which a score is obtained. Subjects were required to answer all the questions except question 9 on driving, which was omitted if the patient did not drive a car when in good health. The scores to the questions were summed and converted to a percentage score, as recommended by Leak et al. (1994). The higher the percentage, the greater the disability and vice versa. The NPRS is a numeric scale to measure the intensity of pain (Jensen et al., 1986; Cole et al., 1994). The scale consists

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of 11 points from 0 to 10 with 0 being ‘‘no pain’’ and 10 being ‘‘pain as worst as it could be’’. 3.3. Data management and analysis Intra-class correlation coefﬁcient (ICC) was used to determine the intra-rater reliability of using the HPSCI. The minimal level of detectable change (MDC) was calculated according to the formula: standard error of measurement ðSEMÞ z-score at the two-sided 95% p conﬁdence intervals ðz ¼ 1:96Þ 2. Independent sample t-tests were used to determine if there were any differences in demographic characteristics and CV angle between the control and neck pain groups. Pearson’s

Fig. 2. Measuring the CV angle by using the Head Posture Spinal Curvature Instrument.

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correlation coefﬁcient was used to investigate the relationship between the CV angle, neck pain disability and severity. SPSS 10.0 for Windows was used for statistical analysis.

4. Results A total of 62 subjects (22 males and 40 females) and 52 subjects (16 males and 36 females) were recruited in the neck pain group and non-neck pain (control) group, respectively. The demographic characteristics of these subjects are shown in Table 1. The distribution of male and female subjects in both groups was comparable. Results demonstrated that there was no signiﬁcant difference in age between the two groups ðp ¼ 0:916Þ. However, CV angle of the neck pain group (mean 49.93, SD 6:08) was signiﬁcantly smaller ðpo0:000Þ than that in the control group (mean 55.02, SD 2:86). The ICC of using the HPSCI with all the subjects (in both groups) was 0.98. The SEM was 1.696 and the MDC was 3.611. Pearson product–moment correlation coefﬁcients between the CV angle, age, neck disability score (NPQ), NPRS and history of neck pain are shown in Table 2. Results demonstrated that CV angle was negatively correlated with NPQ ðrp ¼ 0:395; p ¼ 0:002; R2 ¼ 15:6%Þ and NPRS ðrp ¼ 0:329; p ¼ 0:009; R2 ¼ 10:8%Þ. That is, the greater the CV angle, the lower the NPQ and NPRS scores and vice versa. It was also negatively correlated with age ðrp ¼ 0:380; p ¼ 0:002; R2 ¼ 14:4%Þ. That is, the older the subject, the smaller the CV angle and vice versa. When correlation evaluation was adjusted for age, the CV angle was negatively correlated with NPQ ðrp ¼ 0:3101; p ¼ 0:015Þ but showed no signiﬁcant correlation with NPRS ðrp ¼ 0:1848; p ¼ 0:154Þ (Table 3). No relationship was found between CV angle and the duration of neck pain ðrp ¼ 0:002; p ¼ 0:988Þ. A positive correlation was found between NPQ and NPRS ðrp ¼ 0:649; pp0:000Þ. That is, the higher the NPQ, the higher the NPRS and vice versa. Age was positively correlated with NPRS ðrp ¼ 0:470; pp0:000Þ and NPQ

Table 1 Demographic characteristics of the subjects

Age (years) Northwick Park Neck Pain Questionnaire score (%) Numeric Pain Rating Scale Craniovertebral angle (degree) Duration of neck pain (years)

p value of between group difference

Neck pain group

Control group

Mean standard deviation

Mean standard deviation

39:92 10:80 31:90 15:41

42:33 11:18 Not applicable

0.916 Not applicable

3:87 1:82 49:93 6:08 2:61 2:64

Not applicable 55:02 2:86 Not applicable

Not applicable o0:000 Not applicable

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Table 2 Pearson’s correlation between CV angle, age, NPQ, NPRS and history of neck pain CV angle

Duration of neck pain

NPRS

NPQ

Age

CV angle

1.000

0.002 p ¼ 0:988

0.329** p ¼ 0:009 R2 ¼ 10:8%

0.395** p ¼ 0:002 R2 ¼ 15:6%

0.380** p ¼ 0:002 R2 ¼ 14:4%

Duration of neck pain

0.002 p ¼ 0:988

1.000

0.023 p ¼ 0:858

0.110 p ¼ 0:396

0.073 p ¼ 0:574

NPRS

0.329** p ¼ 0:009

0.023 p ¼ 0:858

1.000

0.649** pp0:000

0.470** pp0:000

NPQ

0.395** p ¼ 0:002

0.110 p ¼ 0:396

0.649** pp0:000

1.000

0.324* p ¼ 0:010

Age

0.380** p ¼ 0:002

0.084 p ¼ 0:517

0.4–0.380** p ¼ 0:002

0.324* p ¼ 0:010

1.000

CV angle: craniovertebral angle; NPQ: Northwick Park Neck Pain Questionnaire; NPRS: Numerical Pain Rating Scale; R2 : coefﬁcient of determination. * Correlation is signiﬁcant at the 0.05 level (2-tailed). ** Correlation is signiﬁcant at the 0.01 level (2-tailed).

Table 3 Pearson’s correlation between CV angle, NPQ and NPRS (adjusted for age) CV angle

NPRS

NPQ

CV angle

1.000

0.1848 p ¼ 0:54

0.3101* p ¼ 0:015

NPRS

0.1848 p ¼ 0:54

1.000

0.5952* pp0:000

NPQ

0.3101* p ¼ 0:015

0.5952* pp0:000

1.000

CV angle: craniovertebral angle; NPQ: Northwick Park Neck Pain Questionnaire; NPRS: Numerical Pain Rating Scale. * Correlation is signiﬁcant at the 0.05 level (2-tailed).

ðrp ¼ 0:324; pp0:000Þ. That is, the older the subject, the higher the NPRS and NPQ and vice versa.

5. Discussion The intra-rater reliability (ICC) of using HPSCI to measure CV angle was ICC ¼ 0:98 in this study, which was consistent with the previous ﬁnding by Wilmarth and Hilliard (2002) ðICC^0:9Þ. The SEM was 1.696 and MDC was 3.611. This indicated that a given clinician could reliably monitor head posture through the CV angle using HPSCI. Further study on the inter-rater reliability of the HSPCI should be performed as this would give greater ﬂexibility for different therapists or medical professionals to follow patients’ progress. The MDC is the lowest change that can conﬁdently be considered as exceeding measurement error and noise.

Results of the present study showed that the CV angle in neck pain subjects was signiﬁcantly smaller than that in normal subjects. We consider that this is clinically signiﬁcant as the difference (51) is 38.8% bigger than the MDC (3.61). Thus, in this sample, subjects with neck pain revealed a signiﬁcant forward head posture when compared to the subjects without neck pain. Johnson (1998) suggested that prolonged forward head posture might increase loading to the non-contractile structures and abnormal stress on the posterior cervical structures and cause myofascial pain. Further study is required to ﬁnd out whether this 51 difference in forward head posture could lead to a signiﬁcant increase in stress on the posterior cervical region in subjects with neck pain. The results also showed that there were moderate degrees of relationships between NPQ and CV angle ðr ¼ 0:395Þ and between NPRS and CV angle ðr ¼ 0:329Þ (Portney and Watkins, 2000). CV angle was negatively correlated with NPQ and NPRS. This was consistent with our hypothesis. The smaller the CV angle (that is, the more forward head posture), the higher the NPQ and NPRS scores and vice versa. However, no causal relationship could be established in this correlation study. The correlation between CV angle and NPQ and NPRS were only moderate at best, suggesting that forward head posture is only one of the factors relating to neck pain and disabilities. The coefﬁcient of determination ðR2 Þ might reveal that about 10–15% of the level of pain and disability could be attributed to neck posture (if it were a causative relationship). There are a number of other factors, for example, osteoarthritis changes, repetitive strain, overuse syndromes and psychological factors that can contribute to the level of

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neck pain and disabilities (Borenstein et al., 1996). Further studies are required to elucidate this. When correlation evaluation was adjusted for age, CV angle was not signiﬁcantly correlated with NPRS, indicating that age is a confounding factor in this relationship. Moreover, pain intensity is only one of the dimensions addressed in the disability of neck pain. Chiu et al. (2005) also reported a weak correlation between intensity of pain and physical impairments, which included an active range of motion and isometric neck muscle strength in patients with chronic neck pain. There was still a moderate degree of relationship between CV angle and NPQ even when age was taken into account. This may give support to the fact that disability assessment is multi-dimensional and can provide a more complete picture of the presenting clinical problem. Clinically, the measurement of CV angle by HPSCI can provide us with further objective information to monitor patients’ conditions. We can measure patients’ CV angle objectively and attempt to correlate this with patients’ pain level and disability. Measures of the CV angle can also be used to document changes in cervical posture due to various interventions, such as exercise programs or postural education. The ﬁnding that the NPQ and NPRS were positively correlated ðrp ¼ 0:649Þ is consistent with a previous study (Hermann and Reese, 2001). Hermann and Reese reported that physical impairments (which included cervical spine range of motion and cervical muscle force), pain intensity, disability and functional limitation were positively correlated in patients with cervical spine disorder. As pain intensity is one of the dimensions measured in NPQ, a positive correlation would be expected. Age was also negatively correlated with CV angle. That is, the older the subject, the smaller the CV angle. This result is consistent with the ﬁndings of a study by Dalton and Coutts (1994) who demonstrated that there was a progressive decline in the CV angle of natural head posture with increasing age. However, they did not provide any reason for this progressive change. Also, age was positively correlated with NPQ and NPRS. That is, the older the subject, the more disability and pain they suffered. A recent study also demonstrated that the prevalence of spinal pain (neck and back pain) with disability continues to rise into old age (Webb et al., 2003). In contrast, Cote et al. (1998) reported that the prevalence of low-intensity and low-disability neck pain decreases with age. A longitudinal study may better assess the relationship between age, posture and neck pain (Griegel-Morris et al., 1992). Hanten et al. (2000) suggested that clinical assessment of patients with neck pain should focus on cervical mobility rather than resting head posture. They found that the resting head posture was not signiﬁcantly

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different between patients and the normal population. However, results of the present study revealed a signiﬁcantly different forward head posture in patients with neck pain when compared to the subjects without neck pain. Our ﬁndings also demonstrated a moderate correlation between head posture and disability in patients with neck pain. Therefore, we suggest that clinicians should be aware of the relationship between forward head posture and neck pain. Postural correction and re-education should be considered as an integral part of prevention and management of patients with neck pain.

6. Limitations The major weakness of correlational research is its inability to establish cause-and-effect relationships. However, in view of the lack of documented evidence that exists concerning these common outcome measures, it is essential to demonstrate how these variables are related in patients with chronic neck pain. As the three measurements were made on one occasion with only a short interval between repeated measures, assessor recall bias was likely to be high, possibly inﬂating the level of reliability found (ICC 0.98). There was potential error in attempting to choose which way to read the scale when the indicator fell between two whole numbers (Garrette et al., 1993); we tried to overcome this by recording the smaller degree in order to be consistent. The measurement can be more accurate if an electronic HPSCI with high sensitivity is developed. Furthermore, we did not measure the sagittal plane position of either the cervical, thoracic or lumbar spine. This was another limitation to our study because the CV angle depends on the relative position of the entire spine (Hermann and Reese, 2001). We tried to minimize this error by standardizing the measurement in standing position. Accurate measurement of complete head and neck posture requires a cephalometric radiographic analysis which was not available for this study. Patients with a certain diagnostic label, for example, whiplash and radiculopathy, might have different postural responses. Future investigation in patients with different diagnosis may give us information about the CV angle and disability level with different pathologies. Further study is also required to elucidate the responsiveness of CV angle as measured by the HPSCI in patients with neck pain before this can be recommended as a valid and reliable outcome measuring tool.

7. Conclusion Results demonstrate that there is a high degree of test–retest reliability in measuring the CV angle by using

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the Head Posture Spinal Curvature Instrument (HPSCI). The CV angle in subjects with neck pain is signiﬁcantly smaller than that in normal subjects. The CV angle is negatively correlated with the disability of patients with neck pain. The smaller the CV angle (that is, the more forward head posture), the higher the NPRS score will be and vice versa. We recommend that CV angle as measured by the HPSCI can provide clinicians with further objective information on the disability and severity of patients with neck pain. References Borenstein DG, Wiesel SW, Boden SD. Neck pain: medical diagnosis and comprehensive management. W.B. Saunders Company; 1996. Chiu TW, Lam TH, Hedley AJ. Subjective health measure used on Chinese patients with neck pain in Hong Kong. Spine 2001;26(17):1884–9. Chiu TW, Ku WY, Lee MH, Sum WK, Wan MP, Wong CY, et al. A study on the prevalence of and risk factors for neck pain among university academic staff in Hong Kong. Journal of Occupational Rehabilitation 2002;12(2):77–91. Chiu TW, Lam TH, Hedley AJ. Correlation between physical impairments, pain, disability and patient satisfaction in patients with chronic neck pain. Archives of Physical Medicine and Rehabilitation 2005;86(3):534–40. Cole B, Finch E, et al., editors. Physical rehabilitation outcome measures. Canada: Canadian Physiotherapy Association; 1994. Cote P, Cassidy D, Carroll L. The prevalence of neck pain and related disability in Saskatchewan adults. Spine 1998;23(15):1689–98. Dalton M, Coutts A. The effect of age on cervical posture in a normal population. Grieve’s modern manual therapy—the vertebral column. 2nd ed.; 1994. p. 361–70. Garrette TR, Youdas JW, Madson TJ. Reliability of measuring forward head posture in a clinical setting. Journal of Orthopaedic Sport Physical Therapy 1993;17(3):155–60. Good M, Stiller C, Zauszniewski JA, Anderson GC, Stanton-Hicks M, Grass JA. Sensation and distress of pain scales: reliability, validity, and sensitivity. Journal of Nursing Measurement 2001;9(3):219–23. Griegel-Morris P, Larson K, Mueller-Klaus K, Oatis CA. Incidence of common postural abnormalities in the cervical, shoulder, and

thoracic regions and their association with pain in two age groups of healthy subjects. Physical Therapy 1992;72(6):425–31. Hanten WP, Olson SL, Russell JL, Lucio RM, Campbell AH. Total excursion and resting head posture: normal and patient comparisons. Archives of Physical Medicine Rehabilitation 2000;81: 62–6. Haughie LJ, Fiebert IM, Roach KE. Relationship of forward head posture and cervical backward bending to neck pain. The Journal of Manual & Manipulative Therapy 1995;3(3):91–7. Hermann KM, Reese CS. Relationships among selected measures of impairment, functional limitation, and disability in patients with cervical spine disorders. Physical Therapy 2001;81(3):903–14. Hickey ER, Rondeau MJ, Corrente JR, Abysalh CJ. Reliability of the cervical range of motion (CROM) device and plumb line techniques in measuring resting head posture (RHP). The Journal of Manual & Manipulative Therapy 2000;8(1):10–7. Jensen MP, Karoly P, Braver S. The measurement of clinical pain intensity: a comparison of six methods. Pain 1986;l27:117–26. Johnson GM. The correlation between surface measurement of head and neck posture and the anatomic position of the upper cervical vertebrae. Spine 1998;23(8):921–7. Leak AM, Cooper J, Dyer S, William KA, Turner-Sotkes L, Frank AO. The Northwick Park Neck Pain Questionnaire, devised to measure the neck pain and disability. British Journal of Rheumatology 1994;33(5):469–74. Portney LG, Watkins MP. Foundations of clinical research applications to practice. 2nd ed. Prentice-Hall Health; 2000. p. 494. Szeto GP, Straker L, Raine S. A ﬁeld comparison of neck and shoulder postures in symptomatic and asymptomatic ofﬁce workers. Applied ergonomics 2002;33(1):75–84. Watson DH. Cervical headache: an investigation of natural head posture and upper cervical ﬂexor muscle performance. Grieve’s Modern Manual Therapy—The Vertebral Column. 2nd ed.; 1994: p. 349–60. Webb R, Brammah T, Lunt M, Urwin M, Allison T, Symmons D. Prevalence and predictors of intense, chronic and disabling neck pain back pain in the UK general population. Spine 2003;28(11): 1195–202. Willford CH, Kisner C, Glenn TM, Sachs L. The interaction of wearing multifocal lenses with head posture and pain. Journal of Orthopaedic and Sports Physical Therapy 1996;23(3):194–9. Wilmarth MA, Hilliard TS. Measuring head posture via the craniovertebral angle. Orthopaedic Physical Therapy Practice 2002; 14(1):13–5.

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Original article

Sacroiliac joint fusion and the implications for manual therapy diagnosis and treatment$ Gali Dara,b,, Sam Khamisc, Smadar Pelega, Youssef Masharawia,d, Nili Steinberga,e, Natan Peledf, Bruce Latimerg, Israel Hershkovitza,g a Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv 69978, Israel Department of Physical Therapy, Faculty of Social Welfare & Health Studies, Haifa University, Mount Carmel, Haifa 31905, Israel c Gait and Motion Laboratory, Department of Orthopedics, Dana Children’s Hospital, Sourasky Medical Center, Israel d Spinal Research Laboratory, Department of Physical Therapy, School of Health, Tel-Aviv University, Tel-Aviv 69978, Israel e Zinman College of Physical Education and Sports Sciences, Wingate Institute, Netanya, Israel f Department of Radiology, Carmel Medical Center, Haifa 34362, Israel g Cleveland Museum of Natural History, Cleveland, OH, USA

b

Received 2 November 2005; received in revised form 27 October 2006; accepted 5 December 2006

Abstract The present paper examines gender differences and changes in prevalence of ankylosed sacroiliac joint (SIJ) with age. SIJs of 287 patients (159 males and 128 females), aged 22–93 years, were examined for fusion, using 3-D CT images. Presence, side and location of the fusion along the joint borders were recorded. Fusion of the SIJ was found to be gender and age dependent; present in 27.7% of all males in contrast to only 3.0% in females (po0.001). The phenomenon increased with age in the male population from 5.8% in the 20–39 age cohorts to 46.7% in the 80+ cohort. As mobilization and/or manipulation of a dysfunctional SIJ are common procedures used by manual therapists, the effect that aging has on SIJ mobility requires therapists to alter or change their method with advancing age. r 2007 Elsevier Ltd. All rights reserved. Keywords: Sacroiliac joint; Mobilization; Manipulation; Treatment techniques

1. Introduction Manual therapists (i.e. physical therapists, chiropractors, and osteopaths) administer various procedures when treating sacroiliac joint (SIJ) dysfunction (Mooney, 1997). These treatments are based on the belief that small movements exist in the joint (Kapandji, 1987; Sturesson et al., 1989; Aldernik 1991; Itoi, 1991; Vleeming et al., 1992; Walker, 1992; Oldreive, 1996; Cibulka 2002). Dysfunction of the SIJ is deﬁned as $ Attributed to: Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel- Aviv University, Tel-Aviv 69978, Israel. Corresponding author. Tel.: +972 3 6409495; +972 50 5662054; fax: +972 3 6408287. E-mail address: [email protected] (G. Dar).

1356-689X/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2006.12.002

hypo- or hyper-mobility of the joint in addition to a mal-alignment or change of positioning of the sacrum and ilium bones (e.g. upslip, downslip, outﬂare, inﬂare, torsion) (Dreyfuss et al., 1994; Tulberg et al., 1998; van der Wurff et al., 2000; Cibulka, 2002; Riddle and Freburger, 2002). SIJ dysfunction is usually treated by correcting the mal-alignments with mobilization, manipulation, traction, compression and gliding of the hypo-mobile joint and strengthening the surrounding muscles of the hyper-mobile joints (Cibulka et al., 1986, 1988; Maitland, 1986; Mooney, 1997; Lee, 1999). To increase its movement and correct mal-alignment, manual force is applied at the SIJ line, hence, mobilizing the innominate bones in respect to the sacrum (Maitland, 1986; Cibulka, 2002; Riddle and Freburger, 2002). Occasionally,

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manipulation of the SIJ may involve a sudden forceful thrust (Cibulka et al., 1986, 1988; Cibulka, 2002). In view of the fact that many manual therapeutic procedures rely on SIJ motion, with the aim to move the joint, it is important for manual therapists to be aware of the aging degenerative process at the site and to deduce its implications regarding appropriate treatment. Our aim was to determine the prevalence of SIJ fusion in the adult population (420 years), and explain its clinical implications.

2. Materials and methods The SIJ status was examined in 287 (159 males and 128 females) consecutive patients referred to the Department of Radiology, Carmel Medical Center, between May and July 2005 due to a variety of lower

Fig. 1. Bilateral SIJ fusion as seen on CT images of male subject (volume rendering method).

abdominal complications. The patients were drawn from the metropolitan area of Haifa (the largest city in northern Israel). Patients with spinal diseases such as spondyloarthropathy or diffuse idiopathic skeletal hyperostosis (DISH) were excluded from the study. To obtain 3-D images of the pelvises, the volume rendering method (Phillips Brilliance 64 CT, thickness of sections: 1–2 mm, MAS: 80-250) was used (Figs. 1–3). This application is fast and able to easily visualize 3-D images of the skeleton structures (Figs. 1 and 2). Volume rendering typically assign color and opacity to volume data based on voxel attenuation (radiation absorption depending on the density and material composition of the object) and sum the contributions of each voxel along a line from the viewer’s eye through the data set. The volume rendering renders the entire volume of data rather than just surfaces or maximum intensity voxels, thereby potentially conveying additional information than a surface model. The SIJ was divided into six equal areas. Areas 1–3 were located at the superior part of the joint, above the arcuate line of the innominate bone, while areas 4–6 were located beneath this point. Presence side and location, of fusion were recorded. The SIJ was examined for fusion along the joint using the 3-D technique (Figs. 1 and 2). Multiplanar reformation was used to detect whether the fusion was intra- or extra-articular (Fig. 3). For intra-test reliability, 3-D images of 10 individuals were re-scored three times (week interval) by G.D. For inter-test reliability, 3-D images of 10 individuals were scored by two additional investigators, blinded from each other. Kappa statistics were calculated for both intra- and inter-examiner reliability data. Statistical analysis was performed by the Fisher exact test determining whether an association existed between SIJ fusion and gender and age. Signiﬁcance of difference was set at po0.05.

Fig. 2. Right SIJ fusion as seen on CT images of male subject (left—normal SIJ) (volume rendering method).

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3. Results SIJ fusion was found in 16.7% of the 287 individuals examined. The inter-examiner reliability between the two examiners was K ¼ 0:725 and for intra-examiner reliability K ¼ 0:8. These values present substantial agreement according to Landis and Koch’s (1977) classiﬁcation. The fusion phenomenon is clearly sex and age dependent (Table 1). Fusion was present in 44 males (27.7%) (Figs. 1–3) in contrast to only four females (3.0%) (po0.0001). In fact, the rate among females was even smaller (2.3%), as one of our females with fusion of the joint also manifested an old fracture of the left innominate bone (which could induce the development of the fusion). All fusions were extra-articular. SIJ fusion was found to be age dependent in males, increasing from 5.8% in the 20–39 year cohort to 46.7% among individuals over age 80 (Table 1). The phenomenon among females, however, does not seem to be associated with age. Fusion was present bilaterally in 19 (11.9%) males. Diffuse fusion (areas 1–6) was present in 12 males (7.5%), four were bilateral. Unilateral involvement did not manifest side predilection (po0.05). The superior region was involved in all individuals manifesting the

Fig. 3. Right SIJ fusion as seen on CT images (parallel sections). Note: (a) hilly topography of the fusion; (b) extra-articular fusion; (c) joint cavity is normal with no sclerosis of the subchondral bone.

157

phenomenon. None of the fusion was isolated to the inferior part of the joint. Fusion of the females was at areas 3, 4, just above and under the arcuate line at the most anterior point of the joint.

4. Discussion The current study demonstrated that SIJ fusion is a common phenomenon in a normal adult population, present in 16.7% of the individuals in our sample. It is clearly a male (27.7% of males vs. 3% of females) and age (5.8% in the 20–39 year cohort vs. 46.7% among individuals over age 80) biased phenomena. The fusion is usually of the extra-articular type and occurs mainly on the superior aspects of the SIJ. These ﬁndings are in agreement with studies conducted on skeletal and cadaver populations (e.g. Brooke, 1924; Sashin, 1930; Stewart, 1984; Waldron and Rogers, 1990; Dar et al., 2005). Manual therapists who frequently utilize manual techniques (i.e. mobilization, traction, manipulation) to maintain and increase articular mobility in a hypomobile SIJ (Cibulka et al., 1986; Walker, 1992; Lee, 1999), should, following our data, be aware of the limited compliance of this joint in the elderly male population. Being inattentive to the above possibility, therapist intervention may result in trauma to the joint. Noteworthy is that prior recognition of SIJ fusion is difﬁcult due to the low reliability of the SIJ dysfunction tests (Dreyfuss et al., 1996; Vincent-Smith and Gibbons, 1999; van der Wurff et al., 2000; Freburger and Riddle 2001; Riddle and Freburger 2002), associated mainly with the difﬁculties in palpating SIJ landmarks and estimating the extent of change during various movements (Vincent-Smith and Gibbons, 1999; O’Haire and Gibbons, 2000), and the availability of roentgenograms (in addition to the manual skills of the therapist) which does not improve recognition of fusion, as roentgenograms are poor diagnostic tools in evaluating SIJ fusion (Dar et al., 2005). Our study raises a number of questions: Is mobilization of the SIJ the correct technique for treating SIJ dysfunction in the elderly? Is it possible to mobilize the

Table 1 Distribution of sample studied by age and gender Sex

Males

Females

Total

Age group

N

SIJ fusion (N)

SIJ fusion (%)

N

SIJ fusion (N)

SIJ fusion (%)

N

SIJ fusion (N)

SIJ fusion (%)

20–39 40–59 60–79 80+ Total

17 38 74 30 159

1 6 23 14 44

5.8 15.8 31.1 46.7 27.7

19 45 46 18 128

0 2 1 1 4

0 11.8 0 0 3.0

36 83 120 48 287

1 8 24 15 48

2.7 9.6 20 31.3 16.7

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SIJ in the elderly? Should SIJ mobilization techniques be contraindicated in certain ages? In summary, the results of the current study question the usefulness of applying manual treatments to SIJ in a high proportion of the elderly (with SIJ fusion), since producing the desirable affect of movements is dubious and there is a risk of injury.

5. Conclusions SIJ fusion is a common phenomenon in the elderly male population: 31.1% in the 60–79 age cohort and 46.7% in the 480 years. As pre-treatment diagnosis is problematic, we suggest that manual therapists demonstrate extra care when applying mobilization or manipulation to the SIJ of elderly patients. The risk of injuring the patient by applying force to the area may be much greater than the potential beneﬁts.

Acknowledgments The authors wish to thank Mrs. Phyllis Curchack Kornspan for her editorial services; and to the Dan David Foundation and The Tassia and Dr. Joseph Meychan Chair of History and Philosophy of Medicine for their ﬁnancial support. References Aldernik GJ. The sacroiliac joint: review of anatomy, mechanics, and function. Journal of Orthopedics & Sports Physical Therapy 1991;13(2):71–83. Brooke R. The sacro-iliac joint. Journal of Anatomy (London) 1924;58:299–305. Cibulka MT. Understanding sacroiliac joint movement as a guide to the management of a patient with unilateral low back pain. Manual Therapy 2002;7(4):215–21. Cibulka MT, Rose SJ, Delitto A, Sinacore DR. Hamstring muscle strain treated by mobilizing the sacroiliac joint. Physical Therapy 1986;66(8):1220–3. Cibulka MT, Delitto A, Koldehoff RM. Changes in innominate tilt after manipulation of the sacroiliac joint in patients with low back pain. An experimental study. Physical Therapy 1988;68(9):1359–63. Dar G, Peleg S, Masharawi Y, Rothschild BM, et al. Sacroiliac joint bridging: demographical and anatomical aspects. Spine 2005; 30(15):E429–32. Dreyfuss P, Dryer S, Grifﬁn J, Hoffman J, Walsh N. Positive sacroiliac screening tests in asymptomatic adults. Spine 1994;19(10):1138–43.

Dreyfuss P, Michaelsen M, Pauza K, Nclarty J, Bogduk N. The valua of medical history and physical examination in diagnosing sacroiliac joint pain. Spine 1996;21(22):2594–602. Freburger JK, Riddle DL. Using published evidence to guide the examination of the sacroiliac joint region. Physical Therapy 2001;81(5):1135–43. Itoi E. Roentgenographic analysis of posture in spinal osteoporotics. Spine 1991;16(7):750–6. Kapandji A. The physiology of the joints. 2nd ed. vol. III. The trunk and the vertebral column. New York: Churchill Livingstone; 1987. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977;33:159–74. Lee D. The pelvic girdle. 2nd ed. New York: Churchill Livingstone Inc; 1999. Maitland G. Vertebral manipulation, 5th ed. London: Butterworths Heinemann; 1986. Mooney V. Sacroiliac joint dysfunction. In: Vleeming A, Mooney V, Dorman T, Snijders C, Stoeckart R, editors. Movement, stability and low back pain. Edinburgh: Churchill Livingstone; 1997. p. 37–52. O’Haire C, Gibbons P. Inter-examiner and intra-examiner agreement for assessing sacroiliac anatomical landmarks using palpation and observation: pilot study. Manual Therapy 2000;5(1): 13–20. Oldreive WL. A critical review of the literature on the anatomy and biomechanics of the sacroiliac joint. Journal of Manual & Manipulative Therapy 1996;4(4):157–65. Riddle DL, Freburger JK. Evaluation of the presence of sacroiliac joint region dysfunction using a combination of tests: a multicenter intertester reliability study. Physical Therapy 2002;82(8): 772–81. Sashin D. A critical analysis of the anatomy and the pathologic changes of the sacroiliac joints. Journal of Bone and Joint Surgery 1930;12:891–911. Sturesson B, Selvic G, Uden A. Movements of the sacroiliac joints, a roentgen stereo-photogrammetric analysis. Spine 1989;14(2):162–5. Stewart TD. Pathologic changes in aging sacroiliac joints. Clinical Orthopedics 1984;183:188–96. Tulberg T, Blomberg S, Bjorn B, Ranger J. Manipulation does not alter the position of the sacroiliac joint: a roentgen stereophotogrammetric analysis. Spine 1998;23(10):1124–8. van der Wurff P, Meyne W, Hagmeijer RHM. Clinical tests of the sacroiliac joint. A systematic methodological review. Part 1: reliability. Manual Therapy 2000;5(1):30–6. Vincent-Smith B, Gibbons P. Inter-examiner and intra-examiner reliability of the standing ﬂexion test. Manual Therapy 1999;4(2):87–93. Vleeming A, Van Wingerden JP, Dijkstra PF, Stoeckart R, Snijders CJ, Stijnen T. Mobility in the sacroiliac joints in the elderly: a kinematic and radiological study. Clinical Biomechanics 1992;7(3): 170–6. Waldron T, Rogers J. An epidemiologic study of sacroiliac fusion in some skeletal remains. American Journal of Physical Anthropology 1990;83:123–7. Walker JM. The sacroiliac joint: a critical review. Physical Therapy 1992;72(12):903–16.

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Original Article

The reliability of isometric strength and fatigue measures in patients with knee osteoarthritis Christopher J. McCarthya,, Michael J. Callaghanb, Jacqueline A. Oldhamb a

Medical School Building, The University of Warwick, Gibbet Hill Campus, Coventry CV4 7AL, UK b The Centre for Rehabilitation Science, University of Manchester, Manchester M13 9WL, UK Received 24 May 2006; received in revised form 16 October 2006; accepted 5 December 2006

Abstract Patients with knee osteoarthritis have both poor strength and endurance of their quadriceps muscles. It is possible to assess muscle fatigue by monitoring frequency spectrum using electromyography (EMG). This study used the closed kinetic chain approach to muscle assessment. Fifty-ﬁve subjects with knee osteoarthritis were examined twice within 1 week. To test maximum voluntary isometric contraction into extension an isokinetic dynamometer, with a closed kinetic chain ‘‘leg press’’ attachment was used. EMG assessment of signal median frequency was done by measuring median frequency shift associated with fatiguing of muscle during a 60 s isometric contraction at 60% of maximum isometric contraction. Intra-class correlation coefﬁcients with 95% conﬁdence intervals, standard errors of measurement and smallest detectable differences were calculated. Results showed the reliability of the maximum voluntary isometric contraction extension strength test was ICC 0.99 and SEM 3.95 N m. The initial median frequency indices also demonstrated excellent ICC and SEM statistics (ICC 0.84–0.91, SEM 9.2–11 Hz) for the three heads of the quadriceps; however, the fatigue slopes for all three muscles were unreliable with poor ICCs (0.04–0.72) and SDD values (2207–4000%). The assessment of peak muscle torque using a closed kinetic chain isometric technique is reliable, as is the determination of median frequency values for the quadriceps. Error for the assessment of fatigue was of an unacceptable scale. While the use of a closed kinetic chain leg press technique provides a reliable measurement of lower limb strength, EMG power spectrum decrease during an isometric contraction is of little value. r 2007 Elsevier Ltd. All rights reserved. Keywords: Knee osteoarthritis; Reliability; Electromyography

1. Introduction Lower limb muscle strength has been shown to be an important correlate of locomotor function in patients with osteoarthritis of the knee (Hurley, 1999; McCarthy and Oldham, 2004). Patients with osteoarthritis of the knee may suffer from arthrogenous inhibition of their quadriceps muscles due to joint effusion (Young, 1993); thus, muscle function may be more signiﬁcantly affected in these patients than in other knee pain syndromes. Isometric muscle strength has been used as a reliable and valid method of assessing exercise treatment in these Corresponding author. Tel.: +02476 575856.

E-mail address: [email protected] (C.J. McCarthy). 1356-689X/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2006.12.003

patients (Fisher et al., 1991, 1993; Marks, 1993, 1994; Fisher and Pendergast, 1994). However, isolated knee, open kinetic chain testing may be undesirable or even contraindicated in pathological conditions of the knee joint (Palmitier et al., 1991). For example, greater muscle isolation of the quadriceps during open kinetic chain testing has been shown to produce extremely high and potentially damaging tibiofemoral joint shearing forces (Bynum et al., 1995; Wilk et al., 1996). Furthermore, Nisell and Ericson, 1999, demonstrated that patellar compression forces were almost 12 times higher than walking and six times higher than running during open kinetic chain knee extension testing. They advised that patients with patellofemoral pain undergoing open kinetic tests should only perform

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submaximal efforts, a principle at odds with the rationale of strength testing procedures where a maximum voluntary contraction is required. However, the tibiofemoral and patellofemoral stresses generated during OKC testing can be reduced by using a closed kinetic chain ‘‘leg press’’ test (Steinkamp et al., 1993). The reliability of closed kinetic chain isometric peak torque testing has been shown to be excellent with healthy young subjects and subjects with patellofemoral pain (Callaghan et al., 2000) (intra-class correlation coefﬁcients, ICCs of 0.82 and 0.92, respectively) but never established in subjects with knee osteoarthritis. Patients with knee osteoarthritis complain of muscle fatigue and a number of methods of quantifying this effect have been proposed. One method of measuring endurance involves the monitoring of change in the electromyographical (EMG) signal from muscle during a sustained contraction. As a muscle maintains a contraction, a reduction in action potential velocity leads to a reduction in the median frequency of the EMG signal power spectrum (Bigland-Ritchie et al., 1981; Elfving et al., 2000). The rate of median frequency decline has been used as an index of muscle fatigue by a number of authors (Bigland-Ritchie et al., 1983; Dolan et al., 1995). The reliability of EMG spectral shift has been evaluated, using the closed kinetic chain isometric procedure, in the quadricep muscles of 20 young, healthy subjects (Callaghan et al., 2001). Callaghan et al. found inter-visit reliability to be acceptable in vastus medialis oblique (VMO ICC 0.72), vastus lateralis (VL ICC 0.74) but poor in rectus femoris (RF ICC 0.33). Thus, with a distinct lack of evidence, in relation to patients with knee osteoarthritis, this study aimed to evaluate the reliability of closed kinetic chain isometric testing and the rate of decline in EMG median frequency in subjects with knee osteoarthritis.

2. Methods 2.1. Design The study was a intra-rater reliability study. Subjects were asked to perform a replicate assessment of lower limb ‘‘leg press’’ isometric extension strength and sustained sub-maximal isometric contraction on two occasions. The duration between tests was 1 week. The same rater rated all assessments. 2.2. Subjects Ethical permission for the trial was obtained from the Central Manchester Healthcare Trust Local Research Ethics Committee (LREC). Written consent was obtained from subjects according to the declaration of Helsinki (World Medical Association Declaration of

Helsinki, 2004). Subjects were recruited from primary and secondary referrals to a physiotherapy department. Subjects met the American College of Rheumatology’s clinical criteria for knee osteoarthritis (Altman et al., 1991) and had radiological evidence of osteophytes. Subjects had knee pain and had experienced knee pain for at least four of the previous 7 days. Subjects were excluded if they had signiﬁcant hip pathology preventing them from mounting the isokinetic dynamometer and if they had signiﬁcant medical comorbidities contraindicating the participation in exercise activity. Subjects with bilateral or unilateral knee pain were included. The details of the subject’s age, body mass index and pain status can be seen in Table 1. 2.3. Procedure To test maximum voluntary isometric peak torque (N m) into extension, a dynamometer, with a closed kinetic chain ‘‘leg press’’ attachment was used. Patients were positioned in the seat of a Biodex isokinetic dynamometer (Biodex Corp, Shirley, NY, USA) with hip ﬂexion ﬁxed at 901 and the knee angle set at 451 ﬂexion. The most painful knee was tested. Patients had two practice contractions prior to data collection to familiarise themselves with this method. Patients performed three maximum contractions of 10 s duration with a 1-min rest between each contraction. (Callaghan et al., 2000). The mean of the three extension peak torques was calculated and used for subsequent analysis. Isometric muscle testing was used as the measurement of EMG spectral shift can be compromised when the length of the sampled muscle changes i.e. shortens or lengthens during isokinetic testing (Basmajian and DeLuca, 1985). To test the EMG signal from the VMO, VL and RF heads of the quadriceps muscle, during the extension leg press activity, the following procedure was used. The areas chosen for electrode placement were prepared by shaving (if appropriate), abraded by ﬁne sandpaper and cleansed with isopropyl alcohol. Skin impedance was monitored with every effort made to keep the skin impedance between each recording electrode and the reference electrode less than 10 kO (Mannion and Dolan, 1996). Electrode positions were determined by using a protractor and tape measure and were marked Table 1 Age, gender, body mass index (BMI) and pain score on a visual analogue scale (VAS) N ¼ 55

Mean

Standard deviation

Age (yr) Gender (female) BMI Pain VAS (mm)

64.9 59% 29.8 63

9.65 5.34 19

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with indelible ink. The muscles were determined as follows: VMO at 501 from the long axis of the femur and 5 cm from the superior medial border of the patella. The VL at 12–151 from the long axis of the femur and 15 cm from the superior lateral border of the patella. The RF at 7–101 medially in the frontal plane at the mid-point of the muscle belly, halfway between the anterior superior iliac supine and the superior pole of the patella (Lieb and Perry, 1971). A template of all reference points was made with an acetate sheet for each patient to ensure that the identiﬁed landmarks and placement sites were reproducible. Pairs of pre gelled silver/silver chloride surface electrodes (Niko Medical Products, UK) were placed in a bipolar conﬁguration on the skin with the knee in 451 of ﬂexion, parallel to the alignment of the muscle ﬁbres with an inter-electrode distance of 5 cm. Reference electrodes were placed locally on muscles unrelated to those being investigated (Turker, 1993). The electrodes were connected to a TEL 100 M four channel remote ampliﬁer/transmitter system with ﬁltering, offset and gain controls for each channel (Biopac Systems Inc. California USA). This was connected via a cable to a TEL 100D receiver module, which was in turn connected to the MP 100 acquisition unit. There was a bandwidth of 8–500 Hz, ampliﬁed with gain set to 10. The sampling rate for analogue to digital conversion was 1024 Hz. The common mode rejection ratio was 110 dB minimum. Patients were asked to perform a 60 s isometric contraction at a level of 60% of their maximun voluntary isometric contraction, a duration and level of contraction shown to produce fatigue (ArendtNeilsen and Mills, 1988; Arnall et al., 2002). Submaximal tasks have been found easier to perform, more stable, and more reliable than maximal tasks (Yang and Winter, 1983). The 60% contraction level was shown to patients via a computer-generated line on the dynamometer screen. Data collection did not commence until the 60% level was reached and ceased before the patient stopped contracting. Online, real-time analysis of the EMG signal from each muscle was performed by the LabVIEW system (National Instruments, TX, USA). The power spectrum of the EMG signals was obtained using the Fast Fourier Transform technique and median frequency was then computed. The data was exported to Microsoft Excel (Ofﬁce 97), for off line analysis and the raw signal checked for artefacts or signal anomalies. Median frequency was normalised against initial median frequency and a slope of linear regression was derived to indicate median frequency decline. This slope was used to describe the rate of change over the contraction time to express a fatigue rate. Both the initial median frequency and the normalised median frequency slope were recorded, for all three muscles, and used for subsequent analysis.

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2.4. Analysis In order to calculate useful indices of reliability four statistics were calculated intra-class correlation coefﬁcients (ICC1,k) with 95% conﬁdence intervals (CI), standard errors of measurement (SEM) and smallest detectable differences (SDD). The ICC ﬁgure, in isolation, cannot give a true picture of reliability (Rankin and Stokes, 1998) and thus was complemented by derivation of CI. The SEM was calculated by obtaining the square root of the ANOVA error variance. The SDD is derived from the SEM and can be expressed in original units or as a percentage of the parameter’s grand mean. In order to assess for bias between the visits that might suggest an improvement in performance due to an inherent learning effect the 95% limits of agreement were also plotted for maximum voluntary isometric contraction, initial median frequency and median frequency slope for vastus medialis, see Fig. 1. 3. Results The subjects were of the similar age and had levels of pain consistent with previous studies (Hurley and Scott, 1998), (see Table 1). The reliability of the maximum voluntary isometric extension peak torque test was excellent, with an excellent ICC statistic, narrow 95% CIs and low SEM and SDD values (See Table 2). The initial median frequency indices also demonstrated excellent ICC and SDD statistics for all three heads of the quadriceps; however, the fatigue slopes for all three muscles were extremely unreliable with poor ICCs, wide 95% CIs and SDD values ranging from 2207% to 4000%. The limits of agreement plots showed that there was no systematic bias between visits indicative of a learning effect. Variability for median frequency slope was extremely large. 4. Discussion The reliability of measures of lower limb muscular strength and quadriceps muscle fatigue had not been established in patients with knee osteoarthritis, prior to this work. Due to the provocative nature of open kinetic chain in patients with knee pain (Bynum et al., 1995; Wilk et al., 1996) testing the reliability of these measures was undertaken using a less provocative, closed kinetic chain procedure. The inter-visit reliability of the strength and EMG measures was established and a number of conclusions can be drawn from data obtained. The data from this study are in agreement with previous authors in relation to the excellent reliability of

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Fig. 1. Limits of agreement plots for (a) maximum voluntary isometric contraction, (b) VMO initial median frequency and (c) VMO median frequency slope.

the maximum voluntary isometric peak torque measure (Callaghan et al., 2000, 2001). Indeed, the measure was as reliable in older subjects, with knee osteoarthritis, as

in a sample of healthy young subjects (Callaghan et al., 2001). An SDD of 8.4% indicates that changes in a group’s average score of greater than 8.4% can be conﬁdently attributed to a real change in strength rather than to measurement error. Measurement error of such low magnitude suggests that this method of measuring lower limb isometric extensor peak torque may be sensitive enough to be of clinical utility. The method of assessment was universally completed by the study sample with no exacerbations of pain during or after the test being reported. The measurement of the initial median frequency of the power spectrum of the EMG signal also demonstrated excellent reliability. Again, the low SDD values demonstrated would suggest that this measure might be sensitive enough to assess small changes in initial median frequency. Initial median frequency has been found to strongly correlate to muscle morphology and it has been demonstrated that there is a reduction in median frequency and fatigue rate in response to an endurance training programme (Thompson et al., 1992). In addition, small increases in proportions of fast twitch muscle ﬁbres have been observed in male athletes following high intensity training (Jansson et al., 1990). Thus, initial median frequency may offer a useful measure of change in muscle ﬁbre morphology in response to exercise programmes. The limits of agreement plots for both maximum isometric peak torque and initial median frequency show that there was no systematic difference between tests, suggesting that there was little learning effect apparent. Thus, the need for a training visit prior to the collection of baseline data is not necessary. The measurement of rate of decline in median frequency was unreliable, with unacceptable levels of measurement error. This ﬁnding agrees with previous authors who have found similar lack of reliability in the muscles of the back (Roy et al., 1989; Arnall et al., 2002) and neck (Gogia and Sabbahi, 1991; Strimpakos et al., 2005). Previous authors who have demonstrated good reliability with this measure in the quadriceps, have used an isolated open kinetic chain knee extension movement (Kollmitzer et al., 1999), while the current study utilised a closed kinetic chain technique. The ‘‘leg press’’ action will have required the recruitment of multiple extensor agonists and thus torque will not have been generated solely by the quadriceps muscle group. It is likely that during a fatiguing muscle contraction the subject will have altered their recruitment patterns and synchronisation between muscles as well as within individual muscles (Escamilla et al., 1998). Consequently the rate of fatigue within the quadriceps muscles may have been extremely variable. This hypothesis may explain the poor reliability of the decline in median frequency within the three heads of the quadriceps as an alternative/allied hypothesis to random measurement error.

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Table 2 Reliability indices for isometric closed kinetic chain extensor strength, and EMG initial median frequency values for three heads of the quadriceps with their corresponding fatigue slopes n ¼ 55

Mean (95% CI)

ICC(1,k)

95% CI

SEM

SDD (%)

Isometric strength (N m) VMO initial median frequency (Hz) VL initial median frequency (Hz) RF initial median frequency (Hz) VMO fatigue slope (%/min) VL fatigue slope (%/min) RF fatigue slope (%/min)

65.7 (57–73) 61 (58.1–64) 56.1 (53.6, 58.6) 56.7 (54.4–59.1) 0.037 (0.07 to 0.007) 0.012 (0.05 to –0.03) 0.027 (0.06 to –0.003)

0.99 0.84 0.87 0.91 0.04 0.55 0.72

0.89–0.99 0.73–0.91 0.78–0.93 0.85–0.95 0.30 to 0.23 0.33–0.71 0.56–0.83

3.95 5.77 4.54 3.60 0.101 0.784 0.611

8.4 11.0 10.4 9.2 2207 4000 2390

ICC, intraclass correlation coefﬁcient; SEM, standard error of measurement; SDD: smallest detectable difference.

The conclusions of the study can be viewed conﬁdently, however, the study had limitations. The study evaluated intra-rater reliability as the same rater was used for all measurements. While it must be recognised that using the same rater for all tests may reduce measurement error the test–retest reliability results obtained above cannot be conﬁdently extrapolated to a general population as inter-rater considerations were not included in this analysis. Further work would be required, using randomly selected raters to investigate the inter-rater reliability of these measures, before more useful inferences to the clinical arena could be made. However, this work is the ﬁrst to investigate a closed kinetic chain method measuring strength and fatigue in patients with knee osteoarthritis. The closed kinetic chain technique is comfortable and is likely to have produced less shear and stress on the knee than those experienced with open kinetic chain testing (Steinkamp et al., 1993). The measurement of lower limb isometric extensor peak torque and initial median frequency of the three superﬁcial heads of the quadriceps has been shown to be reliable in a sample of patients with knee osteoarthritis.

References Altman RD, Alaranta H, Bloch DA, Borenstein D, Brandt K. The American College of Rheumatology critieria for the classiﬁcation and reporting of osteoarthritis of the hip. Arthritis and Rheumatism 1991;34:505–14. Arendt-Neilsen L, Mills KR. Muscle ﬁbre conduction velocity, mean power frequency, mean EMG voltage and force during submaximal fatiguing contractions of the human quadriceps. European Journal of Applied Physiology 1988;58:20–5. Arnall FA, Koumantakis GA, Oldham JA, Cooper RG. Between-days reliability of electromyographic measures of paraspinal muscle fatigue at 40, 50 and 60% levels of maximal voluntary contractile force. Clinical Rehabilitation 2002;16(7):761–71. Basmajian J, DeLuca C. Muscles alive. Their functions revealed by electromyography, 5th ed. Baltimore; 1985. Bigland-Ritchie B, Donovan E, Roussos C. Conduction velocity and EMG power spectrum changes in fatigue of sustained maximal efforts. Journal of Applied Physiology 1981;51(5):1300–5.

Bigland-Ritchie B, Johanssson R, Lippold O, Woods J. Contractile speed and EMG changes during fatigue of sustained maximal voluntary contractions. Journal of Neurophysiology 1983;50:609–14. Bynum EB, Barrack RL, Alexander AH. Open versus closed kinetic chain after anterior cruciate ligament reconstruction. American Journal of Sports Medicine 1995;23(4):401–6. Callaghan MJ, McCarthy CJ, Al Omar A, Oldham JA. The reproducibility of multi-joint isokinetic and isometric assessments in a healthy and patient population. Clinical Biomechanics 2000;15(9):678–83. Callaghan MJ, McCarthy CJ, Oldham JA. Electromyographic fatigue characteristics of the quadriceps in patellofemoral pain syndrome. Manual Therapy 2001;6(1):27–33. Dolan P, Mannion A, Adams M. Fatigue of the erector spinae muscles. A quantitative assessment using ‘‘frequency banding’’ of the surface electromyography signal. Spine 1995;20(2):149–59. Elfving B, Ne´meth G, Arvidsson I. Back muscle fatigue in healthy men and women studied by elecromyography spectral parameters and subjective ratings. Scandinavian Journal of Rehabilitation Medicine 2000;32(3):117–23. Escamilla RF, Fleisig G, Zheng N, Barrentine SW, Wilk KE, Andrews JR. Biomechanics of the knee during closed kinetic chain and open kinetic chain exercises. Medicine and Science in Sports and Exercise 1998;30(4):556–69. Fisher NM, Gresham G, Pendergast DR. Effects of a quantitative progressive rehabilitation program applied unilaterally to the osteoarthritic knee. Archives of Physical Medicine and Rehabilitation 1993;74(12):1319–26. Fisher NM, Pendergast DR. Effects of a muscle exercise program on exercise capacity in subjects with osteoarthritis. Archives of Physical Medicine and Rehabilitation 1994;75(7):792–7. Fisher NM, Pendergast DR, Gresham GE, Calkins E. Muscle rehabilitation: its effect on muscular and functional performance of patients with knee osteoarthritis. Archives of Physical Medicine and Rehabilitation 1991;72(6):367–74. Gogia P, Sabbahi M. Change in the fatigue characteristics of cervical paraspinal muscles with posture. Spine 1991;16:1135–40. Hurley MV. The role of muscle weakness in the pathogenesis of osteoarthritis. Rheumatic Disease Clinics of North America 1999;25(2):283–98 vi. Hurley MV, Scott DL. Improvements in quadriceps sensorimotor function and disability of patients with knee osteoarthritis following a clinically practicable exercise regime. British Journal of Rheumatology 1998;37(11):1181–7. Jansson E, Esbjornsson M, Holm I, Jacobs I. Increase in the proportion of fast-twitch muscle ﬁbres by sprint training in males. Acta Physiologica Scandinavica 1990;140(3):359–63. Kollmitzer J, Ebenbichler GR, Kopf A. Reliability of surface electromyography measurements. Clinical Neurophysiology 1999;110:725–34.

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Lieb FJ, Perry J. Quadriceps function. An electromyographic study under isometric conditions. Journal of Bone and Joint Surgery (America) 1971;53-A:749–58. Mannion AF, Dolan P. Relationship between myoelectric and mechanical manifestations of fatigue in the quadriceps femoris muscle group. European Journal of Applied Physiology 1996;74:411–9. Marks R. The effect of isometric quadriceps strength training in midrange for osteoarthritis of the knee. Arthritis Care and Research 1993;6(1):52–6. Marks R. The effects of 16 months of angle-speciﬁc isometric strengthening exercises in midrange on torque of the knee extensor muscles in osteoarthritis of the knee: a case study. Journal of Orthopaedic and Sports Physical Therapy 1994;20(2): 103–9. McCarthy CJ, Oldham JA. The reliability, validity and responsiveness of an aggregated locomotor function (ALF) score in patients with osteoarthritis of the knee. Rheumatology (Oxford) 2004;43(4): 514–7. Nisell R, Ericson M. Patellar forces during isokinetic knee extension. Clinical Biomechanics 1999;7(2):104–8. Palmitier RA, An KN, Scott SG, Chao EYS. Kinetic chain exercise in knee rehabilitation. Sports Medicine 1991;11(6):402–13. Rankin G, Stokes M. Reliability of assessment tools in rehabilitation: an illustration of appropriate statistical analyses. Clinical Rehabilitation 1998;12:187–99.

Roy SH, De Luca CJ, Casavant DA. Lumbar muscle fatigue and chronic low back pain. Spine 1989;14:992–1001. Steinkamp LA, Dillingham MF, Markel MD, Hill JA, Kaufman KR. Biomechanical considerations in patellofemoral joint rehabilitation. American Journal of Sports Medicine 1993;21(3):438–44. Strimpakos N, Gioftsos G, Kapreli E, Vasilios K, Oldham JA. Issues in relation to the repeatability of and correlation between EMG and Borg scale assessments of neck muscle fatigue. Journal of Electromyography and Kinesiology 2005;15(5):452–65. Thompson DA, Biedermann HJ, Stevenson JM, MacLean AW. Changes in paraspinal electromyographic spectral analysis with exercise: Two studies. Journal of Electromyography and Kinesiology 1992;2(3):179–86. Turker KS. Electromyography: some methodological problems and issues. Physical Therapy 1993;73(10):698–710. Wilk KE, Escamilla RF, Fleisig G, Barrentine SW, Andrews JR, Boyd ML. A comparison of tibiofemoral joint forces and electromyographic activity during open and closed kinetic chain exercises. American Journal of Sports Medicine 1996;24(4):518–27. World Medical Association Declaration of Helsinki, 2004. Avaliable at /http://www.wma.net/e/policy/b3.htmS. Yang JF, Winter DA. Electromyography reliability in maximal and submaximal isometric contractions. Archives of Physical Medicine and Rehabilitation 1983;64:417–20. Young A. Current issues in arthrogenous inhibition. Annals of Rheumatic Disease 1993;52:829–34.

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Case Report

Posterior glenohumeral stiffness: Capsular or muscular problem? A case report Antonio Poser, Oscar Casonato Physical Therapy Department, Centro di Medicina, Viale Venezia 91, 31015 Conegliano, Italy Received 14 April 2006; received in revised form 12 April 2007; accepted 19 July 2007

Keywords: Posterior glenohumeral capsule; Massage; Impingement syndrome

1. Introduction The impingement syndrome’s aetiology is multifactorial. The mechanical factors potentially contributing to this pathology are altered neuromuscular control, decreased force of the rotator cuff and peri-scapular muscles, the acromion’s morphology and posture and stiffness of the posterior capsule (Michener et al., 2003). Amongst these dysfunctions, the authors want to focus on the retraction of the posterior capsule, which can be seen clinically by a limitation in trans-thoracic adduction and internal rotation. Some authors (Warner et al., 1990; Tyler et al., 2000; Matsen and Artnz, 2004), maintain that a number of patients with impingement syndrome show a decreased trans-thoracic adduction and internal rotation caused by the thickening and shortening of the posterior glenohumeral capsule. From a clinical point of view, Tyler et al. (2000) and Lin and Yang (2006) have demonstrated that there is a strict correlation between loss of trans-thoracic adduction and limitation of internal rotation. The relationship between these two limitations is that 1 cm of transthoracic adduction corresponds to an internal rotation reduction of 41. Harryman et al. (1990), in their study on glenohumeral arthrokinematics, introduced for the ﬁrst time the concept of obligate translation. Obligate translation Corresponding author. Tel.: +39 0438661911; fax: +39 0438661950. E-mail address: [email protected] (A. Poser).

1356-689X/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2007.07.002

means a shifting of the humeral head in the opposite direction from the capsule–ligament structure that is being tensed during the physiological movement. For example, during external rotation, the tension from the capsule and the anterior ligaments provokes a posterior translation of the humeral head. The same authors also noticed that a surgical shortening of the posterior capsule caused an ‘‘abnormal’’ obligate translation in an antero-superior direction during arm ﬂexion. Before this one study, Howell et al. (1998) had already observed this particular obligate translation ‘‘in vivo’’, whilst Werner et al. (2004) and Grossman et al. (2005) conﬁrm the presence of this on cadaver examination. Recently, it has been suspected that this particular mechanism (‘‘abnormal’’ obligate translation) is also one of the inducing factors not only for sub-acromial impingement, but also for athletes’ Superior Labral Anterior Posterior (SLAP) lesions (baseball, volleyball, tennis, swimming, etc.) (Burkhart and Morgan, 1998; Burkhart et al., 2003; Grossman et al., 2005). Even though on cadaver specimens it has been demonstrated that a restricted internal rotation and trans-thoracic adduction is caused by the tensing of the posterior capsule (Ovesen and Nielsen, 1986; Terry et al., 1991; Gerber et al., 2003; Grossman et al., 2005), in a clinical setting it is impossible to selectively isolate the tension exercised by the posterior capsule from the tension exercised by the infraspinatus and teres minor muscles, making it, thus, impossible to tell exactly what is the source of the joint restriction. Excluding the Burkhart et al. (2003) study, which demonstrated the presence of a thickened and retracted

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capsule in professional baseball pitchers playing for many years, there is no anatomical or histological study that can demonstrate the presence of this type of alteration in individuals affected by impingement syndrome. The achievement of functional recovery of joint internal rotation is common practice nowadays both as a treatment result in impingement syndrome cases and as a prevention strategy for athletes (Litchﬁeld et al., 1993; Kamkar et al., 1993; Johansen et al., 1995; Burkhart et al., 2003), even though the conclusive evidence of its efﬁcacy is limited (McClure et al., 2004; Aina and May, 2005). In particular, the McClure et al. (2004) study has demonstrated the existence of a positive relationship between the improvement of joint internal rotation and functionality in patients with impingement syndrome. It seems, therefore, that complete internal rotation needs to be a clinical pre-requisite for normal glenohumeral kinematics and functionality. Even though it is widely accepted that muscular problems may be the cause of a ROM limitation, as regards to a decrease in internal glenohumeral rotation, today’s literature claims it is caused by a stiffness of the posterior capsule. This case report (and the ongoing study) the authors are presenting was born from our doubt that a restricted internal rotation could only be caused by a retraction of the posterior part of the capsule. This study was based on the hypothesis that limitations in the glenohumeral joint internal rotation may be caused, more or less signiﬁcantly, by a contracture of the infraspinatus and teres minor muscles. 2. Case report 2.1. History A 42-year-old male manual worker came to the authors complaining of right shoulder pain, which had persisted for 12 weeks. The symptom’s onset was insidious. The intermittent pain was caused and aggravated by moving the arm beyond 901—of elevation or by—sleeping on the right side. The pain intensity was not so strong as to interfere with working activities and when needed the patient would use NSAIDS and ice packs to alleviate pain. The whole of the shoulder was painful (particularly in the deltoid area), but there was no radiation. The patient did not suffer any pain around the cervical area or in the upper extremity. No other signiﬁcant ﬁndings were noted during any part of the history. 2.2. Objective examination (assessment) The examination did not show any differences on shoulder muscle trophism or signiﬁcant postural

Table 1 Inclusion/exclusion criteria (Lukasiewicz et al., 1999; McClure et al., 2004; Bullock et al., 2005) Inclusion criteria The patient needs to meet at least three of the following criteria Presence of Neer’s sign Positive Hawkins’ test results Painful arc Pain during palpation of the rotator cuff tendons Anterior or lateral shoulder pain Painful resisted abduction Exclusion criteria Previous traumas of the shoulder Surgical operation around the shoulder area Pain originating from the cervical spine Frozen shoulder

asymmetries. Scapulo-humeral rhythm was harmonic, although at the end of the movement there was evidence of a slight restriction of right elevation, with more elevation towards the top of the scapula and pain appearing at the end of the movement. Passive joint range of motion only showed a restricted internal rotation of the right shoulder in abduction at 901 compared to the left shoulder. Manual muscular tests revealed no weaknesses, although resisted abduction provoked pain. Impingement tests were positive, particularly Hawkins’ (Hawkins and Kennedy, 1980) and Yocum’s tests (Yocum, 1983). The active compression test was also positive (O’Brien et al., 1998). The cervical spine did not show any movement restrictions or pain during the articular assessment and both the Spurling (Spurling and Scoville, 1944) and Quadrant test (Maitland, 1986) in extension, lateral ﬂexion and same side rotation proved negative. The sub-acromial impingement diagnosis was conﬁrmed by the patient’s symptomatology matching the inclusion/exclusion criteria identiﬁed by many authors (Lukasiewicz et al., 1999; McClure et al., 2004; Bullock et al., 2005) (see Table 1). 3. Measurements and treatment Before treating the patient, internal rotation joint range of motion was measured with the patient lying supine and with the arm held in 901 abduction. Measurements were taken with an inclinometer. The force applied by the physiotherapist to internally rotate the arm was measured with an electronic dynamometer attached to the patient’s wrist, while a second physiotherapist ﬁxed the scapula to prevent shoulder anteposition (Awan et al., 2002) (Fig. 1). The force used for pre- and post-treatment measurements was identical. Resisted muscle tests in abduction, internal and external rotation, were done as described by Cyriax (Ombregt et al., 1995). The resulting force was measured

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with a dynamometer in order to use the same values for the control test. Lastly, impingement tests (Yocum’s and Hawkin’s) and the active compression test (O’Brien et al., 1998) were done. This test, originally conceived for differentiating an AC lesion from a SLAP lesion, has been considered extremely useful because it tenses the whole of the posterior structure through trans-thoracic adduction, internal rotation and ﬂexion of the humerus. Theoretically, this particular position should cause a greater obligate translation of the head of the humerus. Parentis et al. (2004) noted that the active compression test in its ﬁrst part brings the supraspinatus tendon towards the acromion, making this test similar to impingement tests. Even for these tests, the resulting forces were measured with a dynamometer so they could be reproduced exactly during following control tests. Pain provoked by these tests was measured using a visual analogue scale (V.A.S.) immediately after completion of the tests. In order to treat only the muscle part of the shoulder without affecting the capsule, the patient was positioned prone with the arm held by his side in a relaxed position.

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The patient was given a 7 min massage of the infraspinatus and a 3 min massage of the teres minor. The authors considered that this time of massage was sufﬁcient to have a change in the muscle. The massage was done only over the areas of the infraspinatus that were contracted and painful to palpation and on the whole of the teres minor (given its small size), moving the ﬁngertips in a circular fashion (Fig. 2). The force applied was related to the patient’s capacity to endure pain. All of the prior measurements were retaken on completion of the treatment. The treatment consisted of three sessions given on alternate days. During this week of treatment the patient did not take any medication or change his daily routine. Furthermore, he did not receive any other treatment or practice any exercise at home.

4. Results After the three treatment sessions, joint range of motion in internal rotation had increased by 201, with the initial excursion being 681 and the ﬁnal range 881 (Fig. 3). A clear V.A.S. improvement was visible for all of the administered tests. Resisted abduction decreased from an initial 2.8 to 0; Hawkin’s from 3 to 0.3; Yocum’s from 3 to 0.1 and active compression from 2.3 to 0 (Fig. 4).

5. Discussion The treatment results obtained for this clinical case show how a restricted internal rotation may be caused by the posterior muscle component rather than by a retraction of the posterior capsule. The results obtained from treatment of the painful component of the impingement tests (Hawkin’s and Yocum’s) and the active compression test, support the hypothesis that the excess of obligate translation may be

degrees

Fig. 1. Measurement of internal rotation range and force.

100 90 80 70 60 50 40 30 20 10 0

internal rotation ROM

68

1° pre

78

78

82

78

1° post

2° pre

2° post

3° pre

Fig. 2. Internal rotation measurement before and after each treatment.

88

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3.5

Resisted abduction Hawkins test Active compression test Yocum test

V.A.S.Pain

3 2.5 2 1.5 1 0.5 0

1 pre

1 post

2 pre

2 post

3 pre

3 post

Treatments

Fig. 3. V.A.S. for the various tests: resisted abduction, Yocum test, Hawkins test and active compression test. Fig. 5. (A) Asymmetrical tension of the supraspinatus tendon (arrows) caused by the excessive tension of infraspinatus. (B) After the treatment the infraspinatus tendon is relaxed and the tension inside the supraspinatus tendon is distributed in a well-blended way; IS: infraspinatus; SP: supraspinatus; SC: subscapularis.

Fig. 4. Infraspinatus massage.

caused by the shortening of the posterior structures (capsule/muscles). These tests, in fact, stimulate those structures in a peculiar manner, because they require particular ﬂexion/internal rotation/thoracic adduction movements. Therefore, it is fair to assume that the decrease in pain may be caused by a decrease of the obligate translation and consequently by a decrease of the posterior muscular component. Lastly, it is also interesting to note that the pain provoked by the resisted abduction had diminished. This improvement, though, is not attributable to the obligate translation phenomena as for the other tests, because the test is done in 20–301 of abduction in a situation in which there is no tensing of the posterior structure. This phenomenon could be explained by

assuming that retraction of the posterior muscles keeps the head of the humerus in a slight external rotation, which in turn tenses the anterior part of the supraspinatus tendon and relaxes the posterior part (see Fig. 4). During arm movement this phenomena could provoke a bigger mechanical stimulation of the anterior part of the supraspinatus tendon. This difference in tension between anterior and posterior ﬁbres of the supraspinatus tendon in relation to the rotation state of the humeral head has been demonstrated by Nakajima et al. (2004). When, through treatment, the tension exercised by the infraspinatus/teres minor is decreased, the humeral head goes back to its correct position, promoting thus a uniform distribution of tensions within the supraspinatus tendon (see Fig. 5). Reduction of pain during resisted abduction tests could also be attributable to a decrease of the tension transmitted by the infraspinatus tendon to the supraspinatus tendon, as a result of a muscular relaxation achieved through the massage technique. It is, in fact, well known that there is a certain degree of fusion between the rotator cuff’s tendons (Clark and Harryman, 1992) (see Fig. 6) and this fact leads the authors to believe that a contracture of one of the rotator cuff’s muscles could create an imbalance and therefore a bigger tension of the various tendinous parts that compose the rotator cuff. Another possible explanation of the pain reduction could be the gate control effect due to the massage, but this phenomenon cannot quite prove the decreasing of the pain until the following treatment.

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169

References

Fig. 6. Rotator cuff tendon embrication. In particular, it is evident that supraspinatus posterior ﬁbers and infraspinatus cranial ﬁbers converge. IS: infraspinatus; SP: supraspinatus; SC: subscapularis; BG: bicipital groove; LT: lesser tubercle; GT: greater tubercle.

The massage was done on all of the areas, which felt contracted and painful during palpation, keeping the patient’s arm in a neutral position and without putting any kind of stress on the joint capsule. The particular technique adopted by the authors gave results in joint excursion at every session. Ten minutes were sufﬁcient to verify whether the joint deﬁcit could have been caused by a muscular dysfunction or by a capsular problem. This technique can therefore represent a quick diagnostic tool for evaluating the dysfunctional state of the supraspinatus and teres minor muscles. A similar, or even greater result may be obtained using other manual or neuromuscular techniques, but the fact remains that the authors were able to treat the patient without stressing the joint capsule using this speciﬁc technique. This massage represents a rapid tool for recognizing the presence of a joint restriction which is likely to be muscular in origin. 6. Conclusions This case report suggests that by massaging the infraspinatus and teres minor muscles it was possible to gain 201 of internal rotation in a patient with impingement syndrome. This leads the authors to believe that an internal rotation deﬁcit could also be caused by a contracture of the muscles and not exclusively by a posterior capsule rigidity. It is obviously necessary to do further studies on a large number of cases to conﬁrm this hypothesis and calculate the incidence of the muscular component versus the capsular component. A larger study is now underway to conﬁrm the hypothesis. Acknowledgments We sincerely thank Mr. Phil McClure and Marco Testa for the critical analysis and the helpful hints on this manuscript.

Aina A, May S. A shoulder derangement. Manual Therapy 2005; 10(2):159–63. Awan R, Smith Jay, Boon AJ. Measuring shoulder internal rotation range of motion: a comparison of 3 techniques. Archives of Physical Medicine and Rehabilitation 2002;83:1229–34. Bullock MP, Foster NE, Wright CC. Shoulder impingement: the effect of sitting posture on shoulder pain and range of motion. Manual Therapy 2005;10(1):28–37. Burkhart SS, Morgan CD. The peel-back mechanism: its role in producing and extending type II SLAP lesions and its effect on SLAP repair rehabilitation. Arthroscopy 1998;14:637–40. Burkhart SS, Morgan CD, Kibler WB. The disabled throwing shoulder: Spectrum of pathology part I: pathoanatomy and biomechanics. Arthroscopy 2003;19(4):404–20. Clark JN, Harryman DT. Tendons, ligament, and capsule of the rotator cuff: gross and microscopic anatomy. The Journal of Bone and Joint Surgery 1992;A-74:713–25. Gerber C, Werner CML, Macy JC, et al. Effect of selective capsulorrhaphy on the passive range of motion of the glenohumeral joint. The Journal Bone and Joint Surgery 2003;A-85: 48–55. Grossman MG, Tibone JE, McGarry MH, et al. A cadaveric model of the throwing shoulder: a possible etiology of superior labrum anterior-to-posterior lesions. The Journal of Bone and Joint Surgery 2005;87(A-4):824–31. Harryman DT, Sidles JA, Clark JM, et al. Translation of the humeral head on the glenoid with passive glenohumeral motion. The Journal of Bone and Joint Surgery 1990;A-72:1334–43. Hawkins RJ, Kennedy JC. Impingement syndrome in athletes. The American Journal of Sports Medicine 1980;8:151–8. Howell SM, Galinant BJ, Renzi AJ, Marone PJ. Normal and abnormal mechanics of the glenohumeral joint in the horizontal plane. The Journal of Bone and Joint Surgery 1998;A70:227–32. Johansen RL, Callis M, Potts J, Shall LM. A modiﬁed internal rotation stretching technique for overhand and throwing athletes. The Journal of Orthopaedic and Sports Physical Therapy 1995;21(4):216–9. Kamkar A, Irrgang JJ, Whitney SL. Nonoperative management of secondary shoulder impingement syndrome. The Journal of Orthopaedic and Sports Physical Therapy 1993;17(5): 212–24. Lin JJ, Yang JL. Reliability and validity of shoulder tightness measurement in patients with stiff shoulders. Manual Therapy 2006;11(2):146–52. Litchﬁeld R, Hawkins R, Dillman CJ, et al. Rehabilitation for the overhead athlete. The Journal of Orthopaedic and Sports Physical Therapy 1993;18(2):433–41. Lukasiewicz AC, McClure P, Michener L, et al. Comparison of 3-dimensional scapular position and orientation between subjects with and without shoulder impingement. The Journal of Orthopaedic and Sports Physical Therapy 1999;29(10):574–86. Maitland GD. Vertebral manipulation, 5th ed. London: ButterworthHeinemann; 1986. Matsen III FA, Artnz CT. Sub-acromial impingement. In: Rockwood CA, Matsen III FA, editors. The shoulder. Philadelphia WB: Saunders; 2004. McClure PW, Bialker J, Neff N, et al. Shoulder function and 3-dimensional kinematics in people with shoulder impingement syndrome before and after a 6 week exercise program. Physical Therapy 2004;84:832–48. Michener LA, McClure PW, Karduna AR. Anatomical and biomechanical mechanisms of sub-acromial impingement syndrome. Clinical Biomechanics 2003;18:369–79.

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Nakajima T, Hughes RE, An KN. Effects of glenohumeral rotations and translations on supraspinatus tendon morphology. Clinical Biomechanics 2004;19:579–85. O’Brien SJ, Pagnani MJ, Fealy S, et al. The active compression test: a new and effective test for diagnosing labral tears and acromioclavicular joint abnormality. The American Journal of Sports Medicine 1998;26(5):610–3. Ombregt L, Bisschop P, ter Ver HJ, Van de Velde T. A system of orthopaedic medicine. WB: Saunders; 1995. Ovesen J, Nielsen S. Posterior instability of the shoulder. Acta Orthopaedica Scandinavica 1986;57:436–9. Parentis MA, Jobe CM, Pink MM, Jobe FW. An anatomic evaluation of the active compression test. Journal of Shoulder and Elbow Surgery 2004;4:410–6. Spurling RG, Scoville WB. Lateral rupture of the cervical intervertebral disc. Surgery Gynecology and Obstetrics 1944;78: 350–8.

Terry GC, Hammon D, France P, Norwood LA. The stabilizing function of passive shoulder restraints. The American Journal of Sports Medicine 1991;19(1):26–34. Tyler TF, Nicholas SJ, Roy T, Gleim GW. Quantiﬁcation of posterior capsule tightness and motion loss in patients with shoulder impingement. The American Journal of Sports Medicine 2000;28(5):668–73. Warner JJP, Micheli LJ, Arslanian LE, et al. Patterns of ﬂexibility, laxity and strength in normal shoulders and shoulders with instability and impingement. The American Journal of Sports Medicine 1990;18(4):366–75. Werner CM, Nyffeler RW, Jacob HA, Gerber C. The effect of capsular tightening on humeral head translations. Journal of Orthopaedic Research 2004;22(1):194–201. Yocum LA. Assessing the shoulder: history, physical examination, differential diagnosis and special tests used. Clinics in Sports Medicine 1983;2(2):281–9.

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Manual Therapy 13 (2008) 171–179 www.elsevier.com/locate/math

Technical and Measurement Report

Calibration of an instrumented treatment table for measuring manual therapy forces applied to the cervical spine Suzanne J. Snodgrassa,, Darren A. Rivetta, Val J. Robertsonb a

Discipline of Physiotherapy, The University of Newcastle, Australia School of Health Sciences, The University of Newcastle, Australia

b

Received 2 June 2006; received in revised form 21 March 2007; accepted 16 April 2007

Abstract Manual therapy techniques are commonly used to treat musculoskeletal neck disorders, but little is known about the manual forces applied during cervical spine treatment. Forces may vary between practitioners, and this may affect patient outcomes. This study reports the development of an instrumented treatment table and its calibration for measuring posteroanterior-directed forces applied during cervical spine mobilisation. A treatment table surface was instrumented with seven biaxial load cells to measure manually applied forces in three planes. Accuracy of the system was evaluated using known weights (unloaded and loaded to represent a patient’s body weight), selected to be consistent with the level of forces expected to be applied during cervical mobilisation. Recorded force values strongly correlated with known weights (Pearson’s r ¼ 0.999 to 1.000 for forces applied in different directions and locations, unloaded and loaded). The accuracy of forces in the unloaded condition was very good for vertical forces (mean absolute error 1.1 N, SD 1.5), and reasonably good for horizontal forces (2.8 N, SD 2.4 for mediolateral, 3.4 N, SD 1.5 for caudad-cephalad). In the loaded condition absolute error increased slightly for horizontal forces. The accuracy of measured forces indicates the instrumented table is acceptable for measuring cervical mobilisation forces. Using it allows practitioners to perform manual techniques using their usual clinical technique, however interpretation of force data is limited because it represents force applied to the table rather than at a speciﬁc joint. r 2007 Elsevier Ltd. All rights reserved. Keywords: Manual therapies; Cervical vertebrae; Musculoskeletal manipulations; Biomechanics

1. Introduction Neck pain is prevalent, disabling and costly. Lifetime prevalence of neck pain has been estimated to be 66.7% in a Canadian population (Coˆte´ et al., 1998), and only one-third of those with neck pain experience complete resolution of their symptoms (Coˆte´ et al., 2004). In The Netherlands, the annual total costs of neck pain have been estimated at US$686 million (Borghouts et al., Corresponding author. Discipline of Physiotherapy, The University of Newcastle, Box 24, Hunter Building, Callaghan, NSW 2308, Australia. Tel.: +612 49212089; fax: +612 49217902. E-mail address: [email protected] (S.J. Snodgrass).

1356-689X/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2007.04.002

1999). Manual therapy is regularly used to treat musculoskeletal disorders of the neck, supported by some evidence of its effectiveness in the management of both subacute and chronic neck conditions (Bronfort et al., 2004). The manual forces applied during treatments possibly vary between practitioners, and may lead to inconsistent outcomes for patients (Snodgrass et al., 2006). The extent of variation between treatment applications and the implications of differences between manual therapists are unknown. In order to investigate these differences and evaluate the clinical usefulness of manual techniques for treating neck pain, it is necessary to ﬁrst accurately deﬁne and quantify them. This requires the measurement of the applied manual therapy forces.

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The use of an instrumented treatment table when measuring manual forces allows the research setting to closely replicate the clinical setting. Almost identical to a standard treatment table, an instrumented table permits therapists to perform manual techniques as they would in the clinic. Data can be recorded without the need for any additional instrumentation between the hands of the manual therapist and the patient. Instrumented tables have been used to measure the manual forces applied to the lumbar and thoracic spines during various mobilisation and manipulation techniques (Chiradejnant et al., 2001; Harms et al., 1995; Triano & Schultz, 1997). The most commonly studied spinal mobilisation technique is the posteroanterior (PA) mobilisation as described by Maitland et al. (2005). PA mobilisation consists of an oscillatory force applied to the spinous or articular processes of the spine, usually performed with the patient lying prone so forces are primarily directed downward towards the treatment surface. This differs from manipulation, which involves a high velocity thrust (Maitland et al., 2005). The aim of the present research is to report the development of an instrumented treatment table and its calibration for the purpose of measurement of mobilisation forces applied to the cervical spine.

2. Methods 2.1. Equipment design The instrumented table used to measure cervical mobilisation forces was modelled on one that has been used primarily for measuring lumbar spine mobilisation forces (Chiradejnant et al., 2001, 2002). A padded treatment surface from a standard treatment table (SX3 Physioline Series, Model no. 50251, Chattanooga Group, Inc., Sydney, Australia) was ﬁtted to a steel frame (Fig. 1). The steel frame was constructed with 65 65 mm RHS (rectangular hollow section) that was 3 mm thick. This frame was connected to an 8 mm thick solid steel plate via seven biaxial load cells (Xtran, Model S1W, Applied Measurement Australia, Sydney), with a non-linearity ofo0.015% and hysteresis70.02% of their full scale. The steel plate was welded to a stable steel base with adjustable rubber feet, which enabled the surface of the table to be levelled accurately with the frame sitting on any reasonably level surface. Load cells were attached to the frame and base with high tensile precision fasteners that were placed through lubricated ball-bearing joints in the rod ends of each load cell. Precision alignment of the load cells in each plane was ensured during construction using a milling machine that provided a digital readout of position to .001 mm (Model DB-001, Daewoo, Seoul, Korea). A ‘lean bar’ was constructed parallel to the treatment surface and

attached to the base, so that therapists could lean against the bar without adding additional force to the load cells (Fig. 2; lean bar omitted from Figs. 1 and 3 to allow visualisation of load cells). Load cells were positioned to measure forces applied to the table in three directions. Four load cells measure vertical force (z-direction, labelled 1 through 4 in Fig. 1), two measure mediolateral forces (y-direction, labelled 5 and 6) and one measures caudad-cephalad force (x-direction, labelled 7). The load cells measuring vertical force have a maximum capacity of 750 N, so they can tolerate the body weight of a person lying on the table; the load cells measuring horizontal forces have a maximum capacity of 350 N. Each load cell senses compression and distraction in a single plane and converts this to a voltage signal, negative for compression and positive for distraction. Voltage signals pass through an ampliﬁer (Strain Gauge Signal Conditioner, Model RM-044, Applied Measurement Australia, Sydney) to condition the voltage signal to range from 0 to 10 V, and then through the Powerlabs data acquisition system (ADInstruments, Castle Hill, Australia). Chart software (Version 4.2.4, ADInstruments, Castle Hill, Australia) was used to convert the ampliﬁed voltage signal into Newtons of force, using the appropriate conversions for each load cell (10 V ¼ 750 N for load cells with a 750 N maximum capacity, and 10 V ¼ 350 N for load cells with a 350 N maximum capacity). A sampling rate of 100 Hz was used for each of the seven load cells. All electrical equipment (the distribution box for the ampliﬁers, Powerlabs, computer and monitor) were routed through a mains mufﬂer (Model 2F2F/4-4, Sigtronic Industries Pty Ltd, Sydney, Australia) to reduce extraneous electrical noise from the mains power supply to the building. To calculate the force applied for each of the three planes, the following formulas were used: Vertical force ðzdirectionÞ ¼ Load cell 1 þ Load cell 2

þ Load cell 3 þ Load cell 4, Caudadcephalad force ðxdirectionÞ ¼ Load cell 7, Mediolateral force ðydirectionÞ ¼ Load cell 6 Load cell 5. Chart software combines real time force readings from individual load cells to produce an output for each force direction at 100 Hz. All calculations to determine the force applied in a particular direction are based on the changes in each individual load cell’s reading from a baseline of zero (e.g., the value for load cell 1 in the above formula equates to the force (N) recorded at a point in time (sampled at 100 Hz) minus the baseline level (N) recorded by load cell 1 prior to any application of manual force). Load cells 5 and 6 are positioned so

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173

5 2

1

7

4

3 6

x

y

z

Fig. 1. Schematic of the instrumented treatment table showing the placement of load cells. Load cells 1–4 are positioned to measure vertical force (z-direction), 5 and 6 measure mediolateral force (y-direction) and 7 measures caudad-cephalad force (x-direction).

Fig. 2. Therapist applying cervical mobilisation to a subject lying on the instrumented table, showing lean bar in situ.

that when force is applied towards a patient’s left (if the patient is lying prone), load cell 6 stretches, recording a positive value, and load cell 5 compresses, recording a

negative value (Fig. 1). For this reason, the difference in the values between load cells 5 and 6 is used, rather than the sum, to quantify the mediolateral force.

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2.2. Measurement consistency The accuracy of the instrumented table was determined by measuring the error due to positional loading with known weights. In the vertical direction, weights were placed on the surface of the table. In the horizontal directions, the weights were suspended from a ﬁrst order pulley with stainless steel wire and a 1 kg carrier. The pulley was attached to the bed in different locations using either a stainless steel hook fastened beneath the bed surface, or a G-clamp attached to the bed frame. The horizontal portion of the pulley apparatus was veriﬁed as level using a single bubble level attached to the wire. A right angle aligned the pulley with the table edge to ensure force was exerted perpendicular to it and only a single planar direction of force was measured. Locations on the table where forces were applied are illustrated in Fig. 3. Tests of horizontal forces were performed with the table empty (unloaded condition), and with the table loaded with 76 kg arranged to

represent the average body weight of a person lying on the table (loaded condition). Seventy-six kilograms is the reference body weight for an adult male in the most recent dietary guidelines for Australia and New Zealand (Australian Government Department of Health and Ageing, 2006). The weights used for these experiments were veriﬁed as accurate to within 1–2 g by weighing them on an electronic scale (PM4800 Delta range top pan digital balance, Mettler-Toledo, Port Melbourne, Australia). The maximum weight used for testing in the horizontal directions was less than the vertical direction because previous studies of PA spinal mobilisation suggest that forces are mainly vertical, with minimal force applied horizontally (Chiradejnant et al., 2002; Harms & Bader, 1997; Langshaw, 2001). The following procedure was used to record the forces measured by the table from the application of known weights. For each weight applied to the table, a baseline reading of each load cell was recorded prior to the application of the weight. Five-second readings,

Fig. 3. Technical drawings showing side, front and top views of the instrumented table with speciﬁcations indicating the placement of load cells and the locations used for testing measured forces. The padded treatment surface has been removed in the top and front views, and a simulated skeleton illustrates the relationship of load cell position to location of intended manual force. Labels a through c indicate the locations for vertical force testing. Labels e and i designate the alignment of two hooks attached beneath the surface of the table, centred along the table’s width, used for testing both mediolateral and caudad-cephalad forces with a ﬁrst order pulley. Labels d, f, g, h, and j indicate additional locations for mediolateral force testing using a G-clamp to attach the pulley to the side of the bed frame.

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calculated from 500 data points recorded over 5 s sampling periods at 100 Hz, were taken with the table in equilibrium both before and after the weights were applied. The actual force recorded by the table for each weight was determined by the difference between the before-weight and after-weight mean 5 s force readings for each load cell, using the following formulas: F ðverticalÞ ¼ ðF a1 F b1 Þ þ ðF a2 F b2 Þ þ ðF a3 F b3 Þ þ ðF a4 F b4 Þ, F ðcaudadcephaladÞ ¼ F a7 F b7 , F ðmediolateralÞ ¼ ðF a6 F b6 Þ ðF a5 F b5 Þ, where F is force in Newtons; Fa is the mean 5 s force reading (N) recorded after the application of the weight; Fb is the mean 5 s force reading (N) recorded before the application of weight, and numerical subscripts represent the name of the load cell (e.g., Fa1 is a reading from load cell 1). To determine if there was any drift in the load cells over time, the 76 kg loaded condition was sustained for 20 min. Mean 5 s force readings for each load cell recorded at the start of the 20-min time period were compared with mean 5 s readings recorded at the end.

175

mated or overestimated the known weight. For calculating the mean and SD of the absolute errors for each force direction at each weight value, absolute values were used (i.e., the negative sign was dropped for values that were negative). The unloaded and loaded conditions were analysed separately. Pearson’s r was used to determine the level of correlation between recorded values and known weights, and linear regression calculations indicated whether recorded forces accurately predicted the known weight applied. Intra-class correlation coefﬁcients (ICCs) are reported to give an indication of the reliability of the table when measuring forces applied in different locations. Although ICCs are usually used for test– retest reliability, the table needed to reliably record forces applied in different locations on the table. This is because when comparing forces applied to different patients the location of applied force in relation to the table surface will differ with body type, and if a patient’s position changes slightly. SPSS 12.0 (SPSS Inc., Chicago, USA) was used for statistical analysis.

3. Results 2.3. Data analysis Absolute error was used to determine the accuracy of the forces recorded by the table when compared to known weight values. Absolute error was deﬁned as the difference between the known weight value (converted to N from kg) and the force value recorded by the table for a single direction for that particular weight. Values for absolute error could be either positive or negative, depending on whether the recorded value underesti-

The absolute error of recorded force values was very low for vertical force (mean 1.1 N, SD 1.5, Table 1, Fig. 4) and reasonably low for horizontal forces (Table 1, Figs. 5 and 6). Horizontal forces recorded in the loaded condition had slightly higher absolute errors than forces recorded in the unloaded condition. When there was error, the forces recorded by the table usually underestimated the known weight values. Drift in the load cell readings was negligible over 20 min of sustained

Table 1 Accuracy (absolute error in N) of forces measured by the instrumented treatment table when known weights were applied in each direction for the unloaded and loaded conditions (absolute error ¼ absolute value [known weight in N–force measured by table in N]) Weight kg (N)

0.25 (2.5) 0.5 (4.9) 0.75 (7.4) 1 (9.8) 1.5 (14.7) 2 (19.6) 4 (39.2) 6 (58.8) 8 (78.5) 10 (98.1) 12.5 (122.6) 15 (147.1) 17.5 (171.6) 20 (196.1)

Vertical

Caudad-cephalad

Unloaded

Unloaded

Mediolateral Loaded

Unloaded

Loaded

Mean

SD

Mean

SD

Mean

SD

Mean

SD

Mean

SD

0.06 0.16 0.10 0.41 0.16 0.26 0.50 0.88 1.17 1.53 1.80 2.38 2.69 2.95

0.03 0.21 0.09 0.51 0.18 0.22 0.50 0.82 1.04 1.31 1.64 1.98 2.31 2.63

– 1.50 – 2.13 – 2.88 4.36 4.42 4.85 3.44 – – – –

– 0.54 – 1.31 – 0.94 1.99 0.08 1.64 1.37 – – – –

– 3.49 – 6.29 – 9.63 12.49 12.95 16.86 17.02 – – – –

– 1.27 – 3.56 – 4.23 0.67 3.38 3.55 2.01 – – – –

– 1.04 – 1.58 – 2.07 2.76 2.79 4.24 5.72 – – – –

– 0.53 – 0.82 – 1.01 1.05 1.46 2.63 3.53 – – – –

– 1.24 – 1.97 – 2.82 5.35 4.92 5.38 5.91 – – – –

– 0.38 – 0.51 – 1.16 2.29 1.94 2.39 2.42 – – – –

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176

Vertical accuracy

220 200

Recorded value (N)

180 160 140 120 100 80 a

60

b

40

c

20 0

Reference 0

20

40

60

80 100 120 140 160 180 200 220 Weight value (N)

Fig. 4. Plot of recorded values against known weight values for vertical forces applied in three locations: a ¼ caudad end of table, b ¼ centre, c ¼ cephalad end of table (refer to Fig. 3). Reference line represents 100% accuracy. Regression coefﬁcients (slope gradients) for the three sets of recorded values ranged from .97 to .99 (95% CIsp0.002), po.001. Adjusted R2 for each ¼ 1.000.

Caudad-cephalad accuracy

100

Recorded value (N)

80

60

40

20

0

0

20

40 60 Weight value (N)

80

i(cephalad)

i(cephalad)-loaded

e(caudad)

e(caudad)-loaded

Reference

100

Fig. 5. Plot of recorded values against known weight values for caudad-cephalad forces applied in both unloaded (solid line) and loaded (dotted line) conditions in two locations: i ¼ cephalad end of table, e ¼ caudad end (refer to Fig. 3). The direction of applied force in each location is indicated in brackets. Reference line represents 100% accuracy. Regression coefﬁcients (slope gradients) for recorded values in each direction in each condition ranged from 1.02 to 1.22 (95% CIsp0.19), po.001, Adjusted R2s ranged from 0.994 to 0.999.

loading. The electrical noise inherent in the system equated to approximately 1 N, and was always less than 2 N. For mediolateral forces, there was no difference in the accuracy of forces measured with the pulley attached to a hook and forces measured with the pulley attached using the G-clamp, so tests of force in the mediolateral directions from all locations have been combined in descriptions of reliability and accuracy (Table 1, Figs. 4–6). Pearson’s r values were 0.999 to 1.000 for recorded forces in all directions applied in each location, indicating recorded force values correlated with known weights (po.001). Linear regression indicated that recorded force values accurately predicted the known weight values in both the unloaded and loaded conditions (po.001 for all directions of force applied in each location, Figs. 4–6). ICC (2,1) values for forces recorded in each direction, and for both unloaded and loaded conditions in the horizontal directions, ranged from 0.99 to 1.00 (width of 95% CIp0.8 for any direction or condition).

4. Discussion This paper reports the evaluation of an instrumented treatment table designed to measure the forces applied by practitioners performing manual therapy techniques. Comparisons of the values measured by the table with known weights demonstrate the vertical forces are very accurate. Even with weights as small as 0.25 kg, the absolute error waso0.1 N (Table 1). This high level of accuracy for vertical forces is important, because measures of manual therapy forces during spinal mobilisation indicate that most force is applied vertically (Chiradejnant et al., 2002; Harms & Bader, 1997; Langshaw, 2001). Previous studies reporting accuracy of other instrumented tables found that the percent error or coefﬁcient of variation decreased as larger magnitudes of weight were applied (Chiradejnant et al., 2001; Harms et al., 1995). For vertical forces measured in the present study, the percent error consistently ranged between 0.1% and 3%, to an upper weight of 20 kg (196 N), indicating a very small amount of error consistent across different magnitudes of applied force. For horizontal forces, the level of accuracy was not as high. The percent error decreased with increased loading in the horizontal directions, though the absolute error (actual number of Newtons of error) increased (Table 1). A limitation of this method of calibration is the use of uniaxial static forces, when the intended use of the table is for dynamic force measurement at varying angles. Weights were applied to the table in a uniaxial direction because their value and angle of application could be accurately determined, and because there is no gold standard for comparison of dynamic forces.

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Mediolateral accuracy

100

80 Recorded value (N)

177

60

j(R)

e(L)

i(R)

d(L)

h(R)

i(R)-loaded

g(R)

e(R)-loaded

f(R)

i(L)-loaded

e(R)

e(L)-loaded

d(R)

Reference

j(L)

40

i(L) h(L)

20

g(L) f(L)

0

0

20

40

60

80

100

Weight value (N) Fig. 6. Plot of recorded values against known weight values for mediolateral forces applied in both unloaded (solid line) and loaded (dotted line) conditions in 14 locations: d through j ¼ locations along each side of the table (refer to Fig. 3). The direction of applied force in each location is indicated in brackets: R ¼ right (i.e., to right side of the table, deﬁned by the right side of a person lying prone on the table); L ¼ left. Reference line represents 100% accuracy. Regression coefﬁcients (slope gradients) for recorded values in each direction in both conditions for all locations of applied force ranged from 1.000 to 1.129 (95% CIsp0.14), po.001. Adjusted R2s ranged from 0.996 to 1.000.

This calibration method is consistent with reported methods used for similar instruments (Chiradejnant et al., 2001; Harms et al., 1995). The difference between the known weight values and the forces measured by the table in the horizontal directions could not be attributed to a deﬁnable error inherent in the table design because the percent error decreased and absolute error increased with greater testing weights. Furthermore, the error did not demonstrate a consistent pattern with the application of increasing magnitudes of force; it was not linear nor a curve with a consistent slope with increasing applied force. Therefore, the differences between known weights and measured horizontal forces could only be described as random error. This error is possibly attributable to a minimal amount of friction or resistance to movement in the eight ball-bearings of the rod ends connecting the vertical load cells to the table surface and base. The ball-bearing joints are friction-free according to the manufacturer, and the ability of each ball-bearing to move freely was tested and veriﬁed for each individual load cell while not attached to the bed. However, biaxial load cells are usually used independently. When arranged in the conﬁguration shown in Fig. 1, there is some limitation of the free movement of each load cell as they are connected to each other via the table. However, it was necessary that each load cell remain stationary when in situ because a biaxial load cell does not tolerate excessive force applied in directions other than its single plane for measurement, and measuring force in a single plane requires that the load cell remains aligned with that plane. The conﬁguration of the seven load cells in

the instrumented table prevents excessive extraneous movement. Measuring manual therapy forces requires a balance between the accuracy of measurement and the replication of the clinical setting. Often, the more precise and reliable a measure is in the research setting, the less it reproduces clinical practice. By using an instrumented treatment table to measure cervical mobilisation forces, the manual therapist is unencumbered by any instrumentation that might affect their application of force, and the clinical setting is effectively reproduced. However, there are some limitations when using an instrumented table. The table produces a measurement of force in each of three individual planes of movement, resulting in three force values corresponding to separate directions of movement (see sample force-time curves for a cervical mobilisation in Fig. 7). When manual therapists apply force, they apply a single force at a particular angle that will vary depending on the vertebral level, the technique applied, and the position of the patient and therapist. The measurements recorded for each direction of force can be used to calculate a resultant force, but this is in relation to the table, rather than to the anatomy of the person being mobilised. Furthermore, evaluation of the current instrumented table indicated that forces recorded in the horizontal directions were not as accurate as those recorded in the vertical direction. This may limit conclusions about manual forces that are applied with large components of force at acute angles to the surface of the table. In addition, the forces recorded using an instrumented table can be affected by interaction with the patient.

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Channel 7

-100 -80 -60 -40 -20 0

Channel 8

100 80 60 40 20 0

Channel 9

-100 -80 -60 -40 -20 0

Channel 10

Newtons (N)

178

100 80 60 40 20 0

C7 right unilateral mobilisation (grade III)

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

5.5

6

6.5

7

7.5

8

Seconds

Fig. 7. Force–time curves for a posteroanterior cervical mobilisation applied to the right articular process of C7. Channel 7 displays the caudadcephalad force (negative direction is caudad), Channel 8 the mediolateral force (positive direction is towards the patient’s left), Channel 9 the vertical force (negative is downward on to the patient), and Channel 10 the resultant force, calculated in real time at 100 Hz using the formula qﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃ ðChannel 7Þ2 þ ðChannel 8Þ2 þ ðChannel 9Þ2 .

A patient’s soft tissues, as well as the padding on the table, may absorb some of the force applied. Alternatively, forces applied to the body which are not directed at the target joint, such as the ﬁngers of the therapist resting on the patient, may transfer additional forces to the table surface which are recorded as part of the force applied. Therefore, the measured force should not be described as solely representing the manual force applied to a particular spinal joint, even though the therapist may have been directing their mobilisation at that particular joint. No current non-invasive method can measure the amount of force applied to speciﬁc anatomical structures in vivo. The strain on selected structures during manipulation has been estimated, however, using animal models and cadaveric specimens (Kawchuk et al., 2004; Symons et al., 2002), although these are not without signiﬁcant limitations. Compared to other instrumented tables used for measuring manual forces applied to the lumbar spine (Chiradejnant et al., 2001; Harms et al., 1995), the reliability and accuracy of the current instrumented table appears similar. Although the current table could arguably be used to measure multiple types of manual forces in varying anatomical areas, this study focussed on evaluating its use for measuring cervical mobilisation forces by quantifying the error of very small forces (Table 1) and of forces applied to the head end of the table. Testing the accuracy of small forces is necessary because the range of forces applied to the cervical spine is expected to be less than previously reported lumbar

mobilisation forces, and an early study of cervical mobilisation applied by a small group of clinicians and students supports this (Langshaw, 2001). Although the table was very accurate in recording small forces applied in the vertical direction, forces recorded in the horizontal directions were not as consistent (Table 1). To increase the precision of measurement, future designers of instrumented tables should investigate ways to decrease the effects of individual biaxial load cells on other load cells used in the project, or consider using triaxial load cells. However, triaxial load cells report cross-talk between the three axes of force measurement (3-component force sensor, Type 9016B4, Kistler Instrumente AG, Winterthur, Switzerland; Tri-channel load cell, Model No. 2880, Robert A. Denton, Inc., Rochester Hills, USA). Cross-talk is the effect that a force in one axis has on the force output of the other two orthogonal axes, and it varies betweeno71.5% ando75% of the full scale. This means that if a triaxial load cell with a maximum capacity of 750 N in each direction is loaded in one direction, the maximum effect of that force on the force outputs in the other directions could be up to737 N if the cross-talk rating waso75% of the full scale. This indicates that there is a small amount of inherent error when measuring forces in multiple planes, even with triaxial load cells. Nevertheless, the results of this study show that the accuracy of the biaxial load cells was very high for vertical forces, though not as high for horizontal ones.

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5. Conclusion Instrumented treatment tables can be used for measurement of cervical mobilisation forces applied by manual therapists while replicating the clinical setting. Objective measurement of tri-planar forces means speciﬁc manual techniques can be quantiﬁed, although interpretation of data is limited because the recorded forces represent forces applied to the table rather than to the anatomical joint, and there is some inherent error when simultaneously recording forces in three planes. In the case of this instrument, the error became more apparent for forces measured in the horizontal directions. Feedback about applied forces can potentially be used to train therapists to apply speciﬁc levels of force when performing manual techniques. This should improve the consistency of force application between therapists and help to advance clinical practice in manual therapy.

Acknowledgements The authors wish to thank Andrew Yardy, Instructional Designer from the Faculty of Health, The University of Newcastle for the production of the illustrations; Trevor White, Dean Jeffs and Darren Gorton from the Faculty of Health Workshop at The University of Newcastle for the fabrication of the instrumented table and assistance with technical terminology within this manuscript. References Australian Government Department of Health and Ageing. Nutrient reference values for Australia and New Zealand including recommended dietary intakes. Canberra: National Health and Medical Research Council; 2006.

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Borghouts JAJ, Koes BW, Vondeling H, Bouter LM. Cost-of-illness of neck pain in The Netherlands in 1996. Pain 1999;80(3): 629–36. Bronfort G, Haas M, Evans RL, Bouter LM. Efﬁcacy of spinal manipulation and mobilization for low back pain and neck pain: a systematic review and best evidence synthesis. Spine Journal 2004;4(3):335–56. Chiradejnant A, Latimer J, Maher CG. Forces applied during manual therapy to patients with low back pain. Journal of Manipulative and Physiological Therapeutics 2002;25:362–9. Chiradejnant A, Maher CG, Latimer J. Development of an instrumented couch to measure forces during manual physiotherapy treatment. Manual Therapy 2001;6(4):229–34. Coˆte´ P, Cassidy JD, Carrol L. The Saskatchewan health and back pain survey: the prevalence of neck pain and related disability in Saskatchewan adults. Spine 1998;23(15):1689–98. Coˆte´ P, Cassidy JD, Carrol L, Kristman V. The annual incidence and course of neck pain in the general population: a population-based cohort study. Pain 2004;112(3):267–73. Harms MC, Bader DL. Variability of forces applied by experienced therapists during spinal mobilization. Clinical Biomechanics 1997;12(6):393–9. Harms MC, Milton AM, Cusick G, Bader DL. Instrumentation of a mobilization couch for dynamic load measurement. Journal of Medical Engineering & Technology 1995;19(4):119–22. Kawchuk GN, Wynd S, Anderson T. Deﬁning the effect of cervical manipulation on vertebral artery integrity: establishment of an animal model. Journal of Manipulative and Physiological Therapeutics 2004;27:539–46. Langshaw M. Cervical spine mobilisation: the effect of experience and subject on dose. Undergraduate honours thesis, The University of Sydney, Australia, 2001. Maitland GD, Banks K, English K, Hengeveld E. Maitland’s vertebral manipulation, 7th ed. Oxford: Butterworth-Heinemann; 2005 [chaptetr 7, p. 172–6]. Snodgrass SJ, Rivett DA, Robertson VJ. Manual forces applied during posterior to anterior spinal mobilization: a review of the evidence. Journal of Manipulative and Physiological Therapeutics 2006;29(4):316–29. Symons BP, Leonard T, Herzog W. Internal forces sustained by the vertebral artery during spinal manipulative therapy. Journal of Manipulative and Physiological Therapeutics 2002;25:504–10. Triano J, Schultz AB. Loads transmitted during lumbosacral spinal manipulative therapy. Spine 1997;22(17):1955–64.

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Diary of events

2nd World Congress on Manual Therapy and Sport Rehabilitation, The Spine II, in Roma Italy 6th–8th of February 2009 www.newmaster.it

10th International IFOMT Congress, Rotterdam 8th–13th June 2008 The Scientiﬁc Committee wishes to invite abstract submissions for Platform and Poster Presentations. Instructions are now online and available at www.ifomt2008.nl

Janet G. Travell, MD Seminar Series, Bethesda, USA For information, contact: Myopain Seminars, 7830 Old Georgetown Road, Suite C-15, Bethesda, MD 20814-2432, USA. Tel.: +1 301 656 0220; Fax: +1 301 654 0333; website: www.painpoints.com/seminars.htm E-mail: [email protected]

5th Chiropractic Osteopathy Physiotherapy Annual Undergraduate/Pre-Registration Research Conference ‘‘Moving Forward Through Research and Practice’’ 25th October 2008, Bournemouth, UK. Keymote Speaker: Prof. Gordon Waddell, Rehabilitation What Works, For Who and When? Details on how to submit an abstract and register available soon at www. aecc.ac.uk

If you wish to advertise a course/conference, please contact: Karen Beeton, Associate Head of School (Professional Development), School of Health and Emergency Professions, University of Hertfordshire, College Lane, Hatﬁeld, Herts AL10 9AB, UK. There is no charge for this service.

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Masterclass

Hypermobility and the hypermobility syndrome, Part 2: Assessment and management of hypermobility syndrome: Illustrated via case studies Jane V. Simmondsa,b,, Rosemary J. Keerc,1 a

School of Health and Emergency Professions, University of Hertfordshire, Hatfield AL10 9AB, UK b Hospital of St. John and St Elizabeth, London, UK c Central London Physiotherapy Clinic, Harley Street, London, UK Received 19 October 2007; accepted 6 November 2007

Abstract Joint hypermobility syndrome (JHS) is a largely under-recognised and poorly understood multi-systemic hereditary connective tissue disorder which manifests in a variety of different clinical presentations. The assessment and management of patients with the syndrome is often complicated, requiring a comprehensive patient-centred approach and co-ordinated input from a range of medical, health and ﬁtness professionals. The functional rehabilitation process is frequently lengthy, with education of the patient and family, sensitively prescribed and monitored physical therapy interventions and facilitation of lifestyle and behaviour modiﬁcations being the mainstay of the plan. Two typical but very different case studies are presented, each illustrating key aspects of the assessment and highlighting the variety of management strategies and techniques required by therapists to facilitate successful outcomes. r 2007 Elsevier Ltd. All rights reserved. Keywords: Hypermobility syndrome; Assessment; Management; Functional rehabilitation

1. Introduction Joint hypermobility syndrome (JHS) is an underrecognised and often poorly managed multi-systemic hereditary connective tissue disorder. Because of the ubiquitous nature of connective tissue, JHS may manifest in a variety of different ways. Assessment and management of patients with the syndrome therefore requires a range of strategies and skills. This paper, which is designed to be read in conjunction with the accompanying masterclass article (Simmonds and Keer, Corresponding author at: School of Health and Emergency Professions, University of Hertfordshire, Hatﬁeld AL10 9AB, UK. Tel.: +44 1707 28 6108. E-mail address: [email protected] (J.V. Simmonds). 1 Physiotherapy advisor to the Hypermobility Syndrome Patient Association.

1356-689X/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2007.11.001

2007), illustrates two typical but different presentations of the syndrome. Case study one focuses on the management of a 37-year-old woman, who at the time of writing was still under physiotherapy care. The emphasis in this presentation is on the early to middle management over 4 months of physiotherapy care which combined manual therapy and rehabilitation. It also demonstrates the value of a multi-disciplinary approach as input from a psychologist, neurologist and later a ﬁtness instructor was also utilised. Case study two provides an overview of the management of a 16-year-old male adolescent with JHS and marfanoid habitus. This case describes a range of key assessment techniques and highlights the role of education, goal setting and carefully monitored and prescribed exercises and functional rehabilitation. The case

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also highlights the importance of recognising JHS early on in life when lifestyle behaviours and postural habits can be more easily addressed and modiﬁed.

2. Case one: subjective examination 2.1. Current history A 37-year-old woman, referred to as Mrs. AM, was referred to physiotherapy by a Consultant Rheumatologist for help in managing longstanding wide spread debilitating symptoms associated with JHS. Mrs. AM was married with three children (aged 12, 10 and 2 years old). In addition to caring for her family she made jewellery and hoped to be able to start a business. She had some help with housework each week. Mrs. AM’s complaints/symptoms included: (a) low back pain, which was aggravated by standing, lying supine, sitting, bending, lifting or carrying and walking. Once she had been in a static posture for 10 min or more (such as lying or sitting) she found it very difﬁcult to get up again; (b) upper thoracic and neck pain, which was constant and associated with a left-sided headache and also periods of dizziness. She was unable to identify any aggravating factors, although she felt as if her head was too heavy for her neck and needed additional support, particularly when sitting. Resting helped to ease the pain. The neck pain was associated with clicking; (c) bilateral elbow, wrist and hand (R4L) pain with occasional pins and needles bilaterally in all four ﬁngers, aggravated by jewellery making, cooking, lifting and carrying. Clicking in all the arm joints was associated with the upper limb pain; (d) left hip, bilateral knee (R4L), shin and left ankle pain aggravated by walking and going downstairs; and (e) fatigue. Generally, the pain and dysfunction had been increasing over the last 6 months and also appeared to be worse in the week before her period. She admitted to feel frustrated and depressed and had been taking antidepressants intermittently. Pain medication had been largely ineffective. There were times when she felt she could not cope with demands of family life, which included added pressure of having a son with a disability and also elderly parents in poor health living in another country. There were also symptoms compatible with autonomic nervous system dysfunction. These included dizziness, light-headedness, lack of concentration, forgetfulness, irritability, palpitations and shortness of

breath, which can be indicative of dysautonomia (Gazit et al., 2003). In order to conﬁrm this diagnosis referral to a neurologist was made for further investigation. Dysautonomia has been shown to be an extraarticular manifestation of the JHS (Gazit et al., 2003). This can take the form of orthostatic hypotension, which is a drop in blood pressure on changing position (sitting to standing or lying to sitting) or postural orthostatic tachycardia syndrome (POTS), which is an increase in heart rate of 30 beats a minute or more on changing position. This can produce palpitations and shortness of breath. However, the most common form of dysautonomia in JHS may be orthostatic intolerance, which occurs after a period of standing. The blood vessels in the legs dilate and blood ‘pools’ causing blood pressure to drop. The study by Gazit et al. (2003) showed orthostatic hypotension, POTS and uncategorized orthostatic intolerance in 78% of a cohort of patients with JHS compared to 10% of controls. 2.2. Previous history The problem started in the low back 10 years ago during the pregnancy of her second child. This spread to involve the thoracic and cervical spines over the next few months. Osteopathy gave temporary relief, however the pattern was one of a gradual build up of pain and dysfunction. Four years ago she noticed pain spreading to her elbows, knees and lower limbs. She had been noted to be a ‘bendy’ child and had performed contortionist tricks and ballet. From the age of 14 she had suffered recurrent ankle and wrist sprains. In the past, she had exercised regularly by going to the gym up to three times a week; however, she had not been attending gym for the past 6 months because of increasing neck and knee pain. MRI of her head and neck had found no signiﬁcant abnormalities, although she was told she had ‘wear and tear’ in her cervical spine by the rheumatologist. 2.3. Family history Her second son, aged 10, had recently been diagnosed with JHS and was seeing a specialist physiotherapist for rehabilitation. 2.4. 24-hr pattern She was woken from sleep by low back pain when she turned over. In the morning, she woke feeling tired and heavy in her body and noticed pain in her feet immediately on standing up. The pain and discomfort were activity or posture related and generally accrued during the day such that she had to take a rest sometime in the day.

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Pain intensity was judged to be 8–9/10 on a visual analogue scale (VAS) (where 0 ¼ no pain and 10 ¼ worst pain ever experienced). 2.5. Key subjective features

widespread symptoms including pain and fatigue moderate disability physical de-conditioning signs of ANS dysfunction mild levels of fear avoidance behaviour ‘yellow ﬂags’; anxiety, depression, stress and family pressures.

3. Objective examination The aim of the initial examination was a global functional assessment with more detailed examination of the lumbar spine, pelvis, hips and ankle. Examination of the cervical spine, upper limbs and knees took place over subsequent appointments. 3.1. Standing posture Mrs. AM stood in posterior pelvic tilt, with decreased weightbearing on the left leg, hyperextension of the knees (R4L) and so effectively ‘hanging on the right hip’. Her feet ﬂattened on weightbearing and there was increased pronation in the hind and mid-foot. Her skin was soft and showed marked stretchiness in the phase of taking up slack, as tested by picking up the skin on the back of the hand (Simmonds and Keer, 2007). A number of small paper-thin scars and striae atrophicae were noted. These had been present since the age of 12 and not connected with pregnancy or change in weight.

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(left4right) and left-side ﬂexion particularly associated with neck pain. Forward bending of the spine is one of the manoeuvres in the Beighton score, used to identify hypermobility. Mrs. AM could only reach as far as 3 in below her knees at the time of testing, although in the past she could easily touch the ﬂoor with both palms. She scored positively for the other manoeuvres in the Beighton score and so overall her score was 8 (historically 9)/9. Outside the Beighton scale, other joints including other ﬁngers, thumb, toe and shoulder joints were also hypermobile. She conformed to the 1998 Brighton Criteria for JHS, which is equivalent to the Ehlers–Danlos syndrome hypermobility type, formerly EDS III (Grahame et al., 2000). 3.5. Sitting posture Mrs. AM sat in posterior pelvic tilt and slouched into ﬂexion of the whole spine. In an attempt to ﬁnd stability she crossed the right leg over the left such that the right ankle rested on top of the left knee. 3.6. Sit to stand She used her hands to push up and started the movement with lumbar spine ﬂexion rather than hip ﬂexion. Single leg standing highlighted poor control, with the right sacro-iliac joint unlocking on weight bearing in a trendelenberg pattern. Weight bearing on the left leg was achieved with hip hitching on the right. Hip ﬂexion in standing was difﬁcult on the right with spinal ﬂexion occurring and considerable difﬁculty in lowering of the leg due to poor eccentric control.

3.2. Lumbar spine movements 3.7. Lying supine Forward ﬂexion restricted by pain in the posterior legs and low back. Mrs. AM failed to reach 901 hip ﬂexion, bending forward by over ﬂexing in the lumbar spine. Return from ﬂexion was achieved by extending the lumbar spine. Extension showed a good range of motion with pain at the end of range. Side ﬂexion showed normal range and quality of motion with no pain. 3.3. Thoracic spine movements Restricted movement into extension and rotation with pain on left rotation.

She disliked this position as it produced pain in the back and pelvis, and after 10 min (or more) the whole area felt locked and difﬁcult to move. Active Straight Leg Raise Test (ASLR) (Mens et al., 1997) supine: Lifting right leg difﬁcult, leg heavy. Compression (ASIS) lifting leg much easier. 3.8. Peripheral joint testing Ankle: The left ankle was restricted in all directions except eversion by pain and tightness in the lateral lower leg. 3.9. Muscle testing

3.4. Cervical spine movements Fluctuated between a full range of movement with no pain and moderate restriction, affecting rotation

There was an inability to activate the pelvic ﬂoor or transversus abdominus (assessed by palpation). Attempts at drawing in the abdominal wall and lifting

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the pelvic ﬂoor were made by bracing and breath holding. Weak gluteal muscles. 3.10. Passive physiological movement testing Hip: Right hip rotated into ﬂexion late. 3.11. Accessory movement testing and palpation Spine: Tender, but mobile all levels of the lumbar spine. Joint stiffness in the left costotransverse and intervertebral joints T2–7 and stiffness at left C2/3 joint. Decreased multiﬁdus bulk, decreased gluteal tone and overdevelopment and increased tension in rectus femoris, tensor fascia latae, adductors and piriformis. Ankle: Decreased antero-posterior glide of talus at talo-crural joint. Increased tension in lateral calf musculature. 3.12. Neurological assessment There were no neurological abnormalities detected. 3.13. Key objective findings

widespread joint hypermobility poor movement patterns using end of range positions poor load transference through the pelvis overuse of mobile lumbar spine movement restriction in thoracic and upper cervical spines with overuse of mobile mid cervical spine inability to ﬂex right hip to 901 decreased weightbearing through left leg due to ankle dysfunction ineffective trunk stability strategies.

3.14. Goals

to reduce pain to a manageable level to return to normal life to return to the gym to improve ﬁtness and lose weight.

lateral costal breathing and isolation of low effort pelvic ﬂoor, transverses abdominus and multiﬁdus muscle contraction. This was started in side lying and progressed, once it was effectively being performed, to more functional positions such as sitting, standing and during everyday activities. Manual therapy was also applied to the left ankle. This took the form of joint mobilisations to the talocrural and subtalar joints in combination with muscle release work to the calf and peronei to restore normal biomechanics and mobility. This was followed-up with exercises to re-educate efﬁcient load transference through the ankle and foot and included heel raises and deep knee bend in standing. Posture re-education and joint awareness (pelvis, hip, knee and ankle) were practised in different positions using biofeedback (mirror work, still photographs and video) and progressed using a ‘sit-ﬁt’ to provide an unstable surface initially when sitting and as core stability and postural control improved this was progressed to standing. Joint mobilisations were also applied to the thoracic and cervical spines in combination with muscle release to the erector spinae. The patient found exercising on a half roll (see Fig. 1) (using effective postural stabilising muscle activation) very effective at releasing muscular tension and improving thoracic mobility. Clinically, it appears that hypermobile individuals frequently overuse the global muscle system (Bergmark, 1989) and have difﬁculty recruiting the local postural muscle system. It was helpful therefore to inhibit or ‘switch off’ the dominant global muscle (in this case erector spinae) in order to improve recruitment of the trunk stabilisers, in particular multiﬁdus. During one session, Mrs. AM complained of acute pain in her right thumb and radial side of the wrist. The pain had started 2 days previously after lifting her handbag from the seat of the car. Examination of the way she lifted her bag identiﬁed the lift occurring in ulnar deviation thereby putting strain through the

4. Management Initially, treatment involved a combination of different modalities and focused on the primary area of dysfunction. Manual therapy was performed on the tense overactive muscles around the right hip and sacroiliac joint to improve/restore normal movement. A pelvic Com-Pressor belt (Lee, 2003) was used with extra support across the ASIS to help support the pelvis while the patient developed an effective trunk stabilising pattern. Trunk stabilisation involved re-education of

Fig. 1.

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Fig. 2.

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whereas long standing chronic pain does not always respond in such a quick and clear cut way. Sessions were also used to discuss and address Mrs. AM’s fears and improve her understanding of the condition (Russek, 2000). Mrs. AM was particularly concerned as her son was also affected. Topics included pacing of activities, general information on joint care and problem solving. An example in this case involved re-education of lifting and carrying in order to reduce pain and strain, as discussed above. Working with the patient to resolve particular problems which they may be experiencing helps to give them conﬁdence to return to activities that may have caused problems before and help them return to normal activities. Encouraging a healthy lifestyle with attention to good posture and joint control, avoiding prolonged periods of static postures or repetitive activities and developing a life-long habit of regular exercise to maintain general ﬁtness are all important to enable the patient to have the conﬁdence to manage the condition themselves. Mrs. AM also attended regular counselling sessions with a psychologist, which helped to deal with the stress and pressures in her life. 4.2. Status at 4 months

Fig. 3.

lateral side of the wrist and thumb (see Fig. 2). The muscles which produce radial deviation and hold the wrist in a more neutral position were inactive. Once this was pointed out to Mrs. AM (with the use of mirrors and video) she was able to correct the movement (see Fig. 3), quickly learning to lift objects maintaining the wrist in neutral and instantly abolishing the pain. This was followed up with advice and guidance on exercises to strengthen her wrists and ﬁngers. Therapeutic putty was used to practice ﬁnger joint control, encouraging a good pattern of co-contraction around the ﬁnger joints during different ﬁnger, thumb and gripping movements with attention to maintenance of a neutral wrist posture.

4.1. Comment Finding a way that the patient can instantly change or ‘switch off’ a pain is a great motivator for producing a change in movement patterning and can be utilised in the clinic to facilitate permanent behaviour change. Acute onset of pain through soft tissue strain is often easier and quicker to affect through movement change,

After 4 months of attending physiotherapy (initially twice a week and then once a week reducing to once every 2 weeks), the patient reported that two of the goals had been achieved. There had been a signiﬁcant reduction in pain (VAS 2–3/10), such that pain was now manageable and she had returned to her normal life activities. She felt ready to return to the gym, which she intended to do after the school holidays. In addition, she reported feeling less tired, not needing to rest everyday and better able to stand, sit and walk for longer periods without symptoms. She no longer used the compressor belt. The back, hip, knee, and ankle pain and the elbow, wrist and hand pain had resolved, although she was still troubled by intermittent neck stiffness and pain on turning to the left. This appeared to be related to the amount of activity she had undertaken. Pain in her feet on standing in the morning had also resolved. Objectively, Mrs. AM demonstrated improved trunk stability and joint control. She had changed her sitting posture and no longer rested in a posterior pelvic tilt position. She had a full range of forward trunk ﬂexion and was able to touch the ﬂoor with her hands. Movement patterns, when returning from ﬂexion to the upright position and on moving from sitting to standing were ﬂuent and efﬁcient. The right sacro-iliac joint was more stable on single leg standing and she was able to ﬂex and extend the right hip without discomfort. Results from investigations of the autonomic nervous system by the neurologist showed Mrs. AM to have low blood pressure averaging 80/55 on supine testing.

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Recommendations were to increase her ﬂuid and salt intake and to improve the muscle pump effect from the lower legs through exercise. Following her holiday it is proposed that she will also start on medication. Mrs. AM was ready to return to the gym with the aims of maintaining her joint mobility and muscular strength and improving her cardiovascular ﬁtness. Liaison with a ﬁtness instructor at the gym in order to discuss the speciﬁc needs of the patient in view of her problem areas and the inﬂuence of joint hypermobility was an essential part of the plan. A review appointment, prior to attending the gym, with a further review was suggested 3 months later.

previous 12–18 months and the potential for this to impact on joint biomechanics. MH reported a history of increasing low back pain over the previous 2 years with intermittent radiation into the right and left posterior thighs. The back pain had been further exacerbated in a school physical education session, which involved cross-country running with a pack on his back. MH also reported anterior knee pain, ankle instability and low grade neck pain, all common sites for the manifestation of JHS in the adolescent population (Middleditch, 2003). Understandably, MH and his parents were anxious and concerned about the impact of hypermobility on long-term health, ﬁtness and quality of life.

5. Concluding discussion

6.2. Social history

This case study illustrates a typical presentation of a patient with JHS. People with the condition, may be aware of having been ‘bendy’ or more ﬂexible in their youth and also may have developed intermittent joint aches and pain which subsequently have become more persistent. In the early stages, they may well have been more able to cope, as in Mrs. AM’s case, however, frequently an incident or trauma triggers an exacerbation which progressively gets worse and affects many other areas, rather like a ‘domino effect’. In this example, as with many women, it is the effects on the body of pregnancy, childbirth and then looking after young children that bring the patient to the health practitioner desperate for help (Gurley Green, 2001). Some patients unfortunately report that physical therapy has often had little beneﬁcial effect and at worse resulted in deterioration (Keer, 2003). A full understanding of the condition and the presentation is necessary to avoid a poor result, which often leads to the patient ‘therapist shopping’, getting more frustrated and depressed with the problem becoming progressively more chronic. The approach therefore needs to be holistic, patient centred, speciﬁc and aimed at giving the patient the tools to manage the problem themselves.

MH’s parents were not aware of other family members being hypermobile. However, MH’s father, who was present at the initial assessment, was observed to have hyperextending 1st metacarpo-phalangeal joints and he also reported longstanding persistent low back problems, indicating aspects of hypermobility and potentially JHS.

6. Case two: subjective examination

6.3. Hobbies and sports Usual activities included playing competitive club level squash and recreational cycling. MH had reduced his involvement in physical activity as a result of his pain. 6.4. Lumbar spine MH reported constant low back pain with radiation into the posterior thighs. On the VAS pain ranged from 4/10 on a good day to 7/10 on a bad day. Pain was aggravated by running and sustained period of sitting. Pain sometimes took as long as 2 days to settle. It was generally worse in the morning and eased during the day. Occasionally, the pain increased during the day and this was related to the amount of physical activity undertaken or time spent sitting and studying. Pain did not wake him at night. He slept on a very ﬁrm single bed mattress with one large pillow.

6.1. Current history 6.5. Knees A 16-year-old high school boy, referred to as MH, was referred by a Consultant Rheumatologist for rehabilitation following the diagnosis of JHS. Like many hypermobile people, MH had performed contortionist tricks during his childhood and his parents reported that he had complained of long standing intermittent musculo-skeletal pain from an early age. Of note was the substantial rate of growth of 10 cm over the

Knee pain was mildly—moderately irritable, and was described as an intermittent low grade dull ache, occasionally sharp and localised over the anterior, inferior aspect of the patella (VAS 3/10–5/10). The pain was aggravated by stair climbing, squash and sustained sitting. It was relieved by rest, but could take between 2 h and 2 days to settle.

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6.6. Neck Neck pain was also intermittent, superﬁcial and low grade (VAS 2/10–4/10). This pain was aggravated by sustained postures, particularly relating to long periods of studying. Irritability of this pain was considered mild as neck pain was generally relieved with rest overnight. 6.7. Ankles MH described his ankles as unstable as they frequently ‘‘gave way’’ particularly when fatigued and when running and changing directions in squash. His ankles were not painful. 6.8. Neurological assessment: NAD 6.8.1. Special questions General health: MH had no recent illnesses or surgery. Investigations: recent echocardiogram NAD. Med: nil.

6.8.2. Key subjective features

widespread pain and/or dysfunction including lumbar spine, cervical spine, knees and ankles reduced levels of physical activity—leading to de-conditioning signiﬁcant growth and development leading to potential joint biomechanical changes and imbalances anxiety of both MH and his parents regarding the long-term effects of hypermobility syndrome on health, ﬁtness and quality of life.

7. Objective examination The plan for the objective examination was to assess global functional activity and the extent of the tissue laxity and then to examine the speciﬁc presenting complaints. 7.1. Observation MH was tall and slim with ill-deﬁned musculature. In standing, his chin was protracted and his glenohumeral joints were anteriorly positioned. Furthermore, he had a ﬂattened thoracic kyphosis, a hyperlordosis between L3–S1 and his scapulae were protracted with slight winging on active shoulder elevation. In sitting, MH adopted a slumped position with his pelvis in a posterior pelvic tilt. This position further increased the protracted

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position of his chin and the anterior position of the humeral head in the glenoid fossa. 7.2. Sit to stand Recruitment of the vastus medialis muscles was latent on sit to stand, left more so than right. MH quickly adopted a hip hitch, hip hanging posture and locked one knee into hyperextension once in standing. 7.3. Gait analysis MH had a mild trendelenberg gait pattern and intermittently ﬂicked his knees into hyperextension when walking. He had bilateral pes planus with ﬂattening of the medial arches and excessive pronation of the subtalar joint on weight bearing. These features were corrected when wearing sports footwear which provided good hind and mid foot control. 7.4. Joint and soft tissue assessment There was evidence of widespread joint laxity and he scored 6/9 on the Beighton scale. Outside of the scale, other joints including the glenohumeral joints, metacarpo phalangeal joints and the interphalangeal joints of the ﬁngers and toes also displayed excessive ranges of movement. He had elongated ﬁngers and toes (arachnodactyly) a feature of the Marfanoid Habitus (Grahame, 2003) conﬁrmed by a positive Steinberg’s test which involves instructing the patient to fold his thumb into a closed ﬁst (Staud, 2005). This test is positive if the thumb tip extends beyond the palm of hand. MH had 1 cm of skin laxity when the skin was drawn up above the 3rd metacarpal of the hand. His small pox and BCG scars were thin and papery. Additionally, he had striae atrophicae across the lumbar region of his back and a high arched palate and absence of the lingual frenulum. These ﬁndings conformed with the 1998 Brighton Criteria for benign joint hypermobility (equivalent to Ehlers–Danlos Hypermobility Type III with marfanoid habitus), as described by Grahame et al. (2000). 7.5. Lumbar spine Lumbar spine ﬂexion was restricted by tightness in the hamstrings and pain in the lumbar spine. The tips of ﬁngers reached the mid tibia (usually MH could touch the ﬂoor). There was reduced intervertebral movement between L2–S1 on ﬂexion and visible muscle tightness of the paraspinal muscle groups in the lower lumbar region. Lumbar spine extension was restricted by pain to 201 (MH reported usually being able to double that range). Observable hinging and increased intervertebral movement was observed between the L4/5 and L5/S1 motion segments.

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Lumbar side ﬂexion testing showed a similar movement pattern with increased movement in the lower lumbar segments and stiffness in the upper lumbar segments. On palpation, the lower thoracic and upper lumber accessory intervertebral movements were stiff in all directions, while the lower lumber segments were painful and more mobile on palpation with an ‘‘empty’’ end feel. Erector spinae muscles in the region felt ‘‘ropey’’ when palpated and there were a number of active trigger points in these muscles.

7.10. Balance and proprioception

7.6. Muscle function and testing

MH had difﬁculty recruiting and sustaining contractions of his pelvic ﬂoor muscles and transversus abdominus when assessed in crook lying and four-point kneeling. Delayed recruitment and poor endurance and strength of the gluteal muscles, particularly gluteus medius was evident when performing external rotation of the hip in side lying. This weakness was highlighted in walking where it had been noted earlier that MH walked with a mild trendelenberg gait pattern.

Standing stalk test with eyes open and closed revealed increased perturbation especially when standing on the left foot. MH frequently over shot markers when asked to hop onto designated points on the ﬂoor. The ability to reposition the lumbar spine into the neutral position in four-point kneeling was also poor. 7.11. Key objective findings

widespread joint hypermobility, tissue laxity and pain poor posture and altered movement patterns using end of range positions overuse of the lower segments of the lumbar spine protective spasm and active trigger points in the SCM, trapezius, thoracic and lumbar erector spinae muscles poor recruitment, timing, endurance and strength of local postural and stabilising muscles in the neck, trunk and lower quadrant Poor lumbar spine and lower quadrant proprioception.

7.7. Cervical spine 8. Management Range of movement was ‘‘normal’’ for MH in all directions except for upper cervical and lower cervical ﬂexion, where the para-vertebral muscles were observably tight and appeared to restrict range of movement. Palpation revealed very mobile, mid cervical intervertebral movements with the upper cervical tissues and intervertebral muscles and tissues feeling ‘‘thick and boggy’’. Sternocleido mastoid (SCM) and the upper ﬁbres of trapezius were tight and there was palpable spasm and active trigger points in these muscles.

MH had difﬁculty recruiting the deep neck ﬂexors and his SCM muscles were very over active. Active movements of the neck and shoulders highlighted increased activity of the upper trapezius and SCM muscles with associated shoulder girdle elevation and poor scapulo-humeral rhythm.

The initial management strategy aimed to address the anxiety of MH and his parents with regard to his condition and then to agree to short- and long-term goals. Discussions were had with MH and his parents at the beginning of the rehabilitation programme and at intervals throughout the process in order to alleviate anxiety and provide reassurance regarding the long-term prognosis. It was particularly important to discuss the nature of the condition in the light of his stage of growth and development and the implications of JHS on his involvement in sport and the impact on study habits and home ergonomics. There were also discussions about the importance of changing postural habits and improving stability, strength and endurance through a functional rehabilitation programme and long-term commitment to exercise and physical activity.

7.9. Lower limb

8.1. Short-term goals

The lower limbs were generally well aligned, although the patellae were positioned slightly laterally and superiorly. Timing of the VMO was latent on sit to stand and he quickly snapped into hyperextension. Repeated one legged squatting and deep knee lunges reproduced anterior knee pain symptoms. Ankle inversion and plantar ﬂexion movements were excessive on both active and passive movement of both ankles. Medial arches were ﬂattened on weight bearing and restored when unloaded.

7.8. Muscle function

improve posture and body awareness reduce low back, thigh and knee pain improve upper and lower quadrant muscle strength — endurance and functional stability.

8.2. Long-term goals

improve cardiovascular ﬁtness and sports speciﬁc functional capacity in order to enjoy an active

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sporting lifestyle and prevent further pain and injuries return to playing regular squash and other recreational physical activities adopt a lifelong commitment to exercise and maintain ﬁtness in order to reduce the risk of injury and long-term pain.

8.3. Initial stage Initial treatment sessions consisted of postural reeducation and developing lumbar control through functional activities such as sitting and standing as advocated by Middleditch (2003). This was then progressed to activities such as sitting to standing, walking and bending over with postural control to pick things up. Swiss ball work was also introduced in the early sessions. These activities were complemented by manual therapy techniques such as gentle mobilisations of the upper lumbar and lower thoracic motion segments and soft tissue release of tight thoracic and lumbar para-spinal muscles. MH was also taught the concept of pacing activities, particularly with respect to the long periods of time he spent studying. Ergonomics relating to his desk, position of his computer and chair were also discussed. Carefully prescribed proprioception exercises and strength-endurance exercises training were then gradually instigated to address trunk and lower quadrant stability. Trunk stability training included: training transversus abdominus, the pelvic ﬂoor muscles, the gluteal muscles, the lower and middle ﬁbres of trapezius, multiﬁdus, serratus anterior and deep neck ﬂexors mainly in functional positions, i.e. sitting, standing and four-point kneeling. Furthermore, the poor timing and endurance of vastus medialis and gluteus medius were facilitated in stride standing, mini squats and sit to stand. Like many hypermobile people, MH found isolating and recruiting individual muscle groups difﬁcult and therefore sensory feedback including careful hand placement over speciﬁc muscle groups and around joints, PNF patterning, tape and mirrors were all important to help facilitate muscle activity and appropriate motor control and control of movement. Exercises were initially directed towards training in the inner to middle joint range and were gradually progressed into the outer range where the joints were less stable due to muscle weakness and altered proprioception.

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chain multi-directional exercises were incorporated in order to train more functionally. Stationary cycling and treadmill walking were also included in the rehabilitation programme in order to address aerobic components of ﬁtness. During the middle stage of the programme, the main aims were to develop strength-endurance and to improve motor control, proprioception and improve function. Exercise prescription was carefully monitored and progressed on a week-by-week basis and exercises were prescribed at a level where a minimum of two sets of eight exercises could be achieved with good quality movement and without causing pain. Repetitions were also gradually increased to a maximum number of 25 and sets increased to three to target the endurance element. MH attended the clinic on average, once a week for a further 14 weeks. These sessions were used to monitor the quality of the exercise, further progress of the programme and treat any symptoms that arose as a result of the exercises. 8.5. Final stages During the ﬁnal stages of the programme, sport speciﬁc functional rehabilitation for squash was

8.4. Middle stage Once the lumbar symptoms had begun to settle and a degree of trunk stability had been achieved, a progressive functional rehabilitation circuit training programme was introduced. Exercises in the circuit were initially mainly closed chain in order to enhance proprioceptive feedback and assist with control (Fig. 4). Later, open

Fig. 4.

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addressed by incorporating speciﬁc shadowing drills, running and cutting drills, progressive lower limb plyometric exercises and racquet activities on the minitramp to challenge proprioception (Fig. 5). 8.6. Comment Functional rehabilitation was based on the principles of skill acquisition and motor learning and included concepts of attention focus, self-control/self-efﬁcacy and training in dyads as described by McNevin et al (2000). Also underpinning the rehabilitation were the physiological principles of training (Wilmore and Costill, 2004; Arnold and Gentry, 2005). Improving proprioception is considered to be a key element for the amelioration of symptoms in this patient group (Ferrell et al., 2004) and therefore was a key component in the programme. MH was encouraged to use a training log with personal targets to assist with motivation. Exercises during the ﬁnal phase was aimed at improving higher level function, therefore it was important to monitor quality of movement and to apply the overload principle in order to stimulate training gains and mimic the demands of squash and other higher level activities.

8.7. Discharge and discharge planning MH was discharged from regular physiotherapy rehabilitation sessions after 17 weeks. He described himself as 90–95% better and he felt generally stronger and more physically stable and able. His back pain had almost completely resolved (VAS 0–2) and his knee pain was negligible. The quality and control of his spinal and lower limb movements were much improved, although it was noted that when he was fatigued, old patterns re-emerged. He had returned to playing squash on a recreational basis with plans to compete in the following month. He was also cycling recreationally with no ill effects. MH was advised to continue with a maintenance programme of exercises. The discharge plan included a 1 and 4 month review. With consent from MH and his parents, the school physical education teacher and squash coach will be informed in order to discuss the key issues associated with hypermobility, particularly in relation to reducing the risk of injury and prudence with regard to sudden increases in physical workload.

9. Concluding discussions This case study, reports the assessment and physiotherapy management of an adolescent young man with hypermobility syndrome and marfanoid habitus. Following a thorough examination, discussions with parents, medical consultant and MH, a shared management plan was developed and implemented. It should be highlighted that there were set backs in MH’s progress and that this is a common pattern when managing people with this syndrome. Of particular note were transient joint and soft tissue reactions in the knees and elbows, particularly in the middle stage of rehabilitation when increased load was applied to the joints and soft tissues. These symptoms were addressed by altering the mechanics of the exercise, i.e. avoiding hyperextension of the joints and reducing load either by reducing the lever arm or reducing the resistance and applying tape to assist with proprioception. This case report provides an example of a progressive functional rehabilitation programme implemented at an important developmental stage. Manual therapy in conjunction with clinically reasoned functional rehabilitation and implementation of appropriate behavioural strategies will hopefully lead to long-term amelioration of symptoms and effective self management.

10. Summary

Fig. 5.

Treating and managing patients with JHS can often be slow and very challenging. A patient centred holistic

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approach is recommended. The process frequently involves communicating and co-ordinating input from the multi-disciplinary health and ﬁtness team. Education regarding the nature of the condition and the implications for long-term health, quality of life, sport and physical activity involvement, ergonomics and work routines is an important aspect of the process. Facilitating lifestyle and behaviour changes and carefully administering a range of therapeutic interventions, including manual therapy and functional exercise therapy are central to the management plan. These two case studies illustrate common, but very different clinical presentations of JHS. They highlight the application of key diagnostic criteria and assessment procedures used in the patient examination. They also provide examples of some of the strategies and skills required by therapists to successfully rehabilitate people with the syndrome.

Acknowledgements The authors wish to thank the patients who were included in the masterclass and case studies. We also wish to thank and acknowledge the assistance of Dr. Karen Beeton, Associate Head of School, School of Health and Emergency Professions, University of Hertfordshire, Hatﬁeld, Herts, UK, for her advice in planning and preparing this masterclass. References Arnold P, Gentry M. Strength training: what the team physician needs to know. Current Sports Medicine Reports 2005;4(6):305–8. Bergmark A. Stability of the lumbar spine. A study in mechanical engineering. Acta Orthopedica Scandinavica 1989;230(Suppl.): 20–4.

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Ferrell WR, Tennant N, Sturock RD, Ashton L, Creed G. Amelioration of symptoms by enhancement of proprioception in patients with joint hypermobility syndrome. Arthritis & Rheumatism 2004;50:3323–8. Gazit Y, Nahir M, Graham R, Jacob G. Dysautonomia in the joint hypermobility syndrome. American Journal of Medicine 2003; 115(1):33–40. Grahame R. Hypermobility and the heritable disorders of connective tissue. In: Keer R, Grahame R, editors. Hypermobility syndrome— recognition and management for physiotherapists. Butterworth Heinemann; 2003. p. 15–26 [chapter 2]. Grahame R, Bird H, Child A, Dolan L, et al. The revised (Brighton1998) criteria for the diagnosis of benign joint hypermobility syndrome (BJHS). Journal of Rheumatology 2000;27(7):1777–9. Gurley Green S. Living with the hypermobility syndrome. Rheumatology 2001;40:487–9. Keer RJ. Physiotherapy assessment of the hypermobile adult. In: Keer R, Grahame R, editors. Hypermobility syndrome—recognition and management for physiotherapists. Butterworth Heinemann; 2003. p. 68 [chapter 6]. Lee DG. The thorax. An integrated approach. DG Lee Physiotherapist Corporation; 2003. p. 101. McNevin N, Wulf G, Carlson C. Effects of attention focus, self control and dyad training on motor learning; implications for physical rehabilitation. Physical Therapy 2000;80(4):373–85. Mens JMA, Vleeming A, Snijders CJ, Stam HJ. Active straight leg raising test: a clinical approach to load transfer function of the pelvic girdle. In: Vleeming A, Mooney V, Dorman T Snijders C, Stoeckart R, editors. Movement, stability and low back pain. Edinburgh: Churchill Livingstone; 1997. p. 425–31 [chapter 35]. Middleditch A. Management of the hypermobile adolescent. In: Keer R, Grahame R, editors. Hypermobility syndrome—recognition and management for physiotherapists. Butterworth Heinemann; 2003. p. 51–6 [chapter 5]. Russek LN. Examination and treatment of a patient with hypermobility syndrome. Physical Therapy 2000;80:386–98. Simmonds JV, Keer RJ. Hypermobility and the hypermobility syndrome. Manual Therapy 2007;12(4):298–309. Staud R. Special tests in rheumatology, /http://www.med.uﬂ.edu/ rheum/rheumTests.htm#steinbergS; 2005 [accessed August 2007]. Wilmore JH, Costill DL. Neuromuscular adaptations to resistance training. In: Wilmore JH, Costill DL, editors. Physiology of sport and exercise. 3rd ed. London: Human Kinetics; 2004. p. 84–110 [chapter 3].