MMT book chapter
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MMT book chapter
ARTICLE IN PRESS Manual Therapy 10 (2005) 242–255 www.elsevier.com/locate/math Masterclass Diagnosis and classification of chronic low back pain disorders: Maladaptive movement and motor control impairments as underlying mechanism Peter O’Sullivana,b, a Body-logic Physiotherapy, 146 Salvado Rd, Wembley, WA 6014, Australia School of Physiotherapy, Curtin University of Technology, Perth, Western Australia b Received 3 April 2005; accepted 9 July 2005 Abstract Low back pain (LBP) is a very common but largely self-limiting condition. The problem arises however, when LBP disorders do not resolve beyond normal expected tissue healing time and become chronic. Eighty five percent of chronic low back pain (CLBP) disorders have no known diagnosis leading to a classification of ‘non-specific CLBP’ that leaves a diagnostic and management vacuum. Even when a specific radiological diagnosis is reached the underlying pain mechanism cannot always be assumed. It is now widely accepted that CLBP disorders are multi-factorial in nature. However the presence and dominance of the patho-anatomical, physical, neuro-physiological, psychological and social factors that can influence the disorder is different for each individual. Classification of CLBP pain disorders into sub-groups, based on the mechanism underlying the disorder, is considered critical to ensure appropriate management. It is proposed that three broad sub-groups of CLBP disorders exist. The first group of disorders present where underlying pathological processes drive the pain, and the patients’ motor responses in the disorder are adaptive. A second group of disorders present where psychological and/or social factors represent the primary mechanism underlying the disorder that centrally drives pain, and where the patient’s coping and motor control strategies are mal-adaptive in nature. Finally it is proposed that there is a large group of CLBP disorders where patients present with either movement impairments (characterized by pain avoidance behaviour) or control impairments (characterized by pain provocation behaviour). These pain disorders are predominantly mechanically induced and patients typically present with mal-adaptive primary physical and secondary cognitive compensations for their disorders that become a mechanism for ongoing pain. These subjects present either with an excess or deficit in spinal stability, which underlies their pain disorder. For this group, physiotherapy interventions that are specifically directed and classification based, have the potential to impact on both the physical and cognitive drivers of pain leading to resolution of the disorder. Two case studies highlight the different mechanisms involved in patients with movement and control impairment disorder outlining distinct treatment approaches involved for management. Although growing evidence exists to support this approach, further research is required to fully validate it. r 2005 Elsevier Ltd. All rights reserved. 1. The need to classify CLBP disorders Low back pain (LBP) is common with up to 80% of people reporting LBP over their life time (Dillingham, 1995). The majority of acute LBP disorders resolve Corresponding author at: Body-logic Physiotherapy, 146 Salvado Rd, Wembley, WA 6014, Australia. E-mail address: [email protected]. 1356-689X/$ - see front matter r 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2005.07.001 within a 4 week period although recurrence is common (Croft et al., 1998). A small number of disorders (10–40%) become chronic and represent a major cost burden for society (Dillingham, 1995; Croft et al., 1998). In spite of the small number of pathological conditions that can give rise to back pain, most cases (85%) are classified as ‘‘non-specific’’ because a definitive diagnosis cannot be achieved by current radiological methods (Dillingham, 1995). Even when a specific diagnosis is ARTICLE IN PRESS P. O’Sullivan / Manual Therapy 10 (2005) 242–255 made, the validity of the diagnosis can often be questioned. This leaves a diagnostic and management vacuum (Leboeuf-Yde et al., 1997). This situation commonly results in the ‘‘signs and symptoms’’ of the disorder being treated without consideration for the underlying basis or mechanism for the pain disorder. It is well recognized that the classification of chronic low back pain (CLBP) disorders into homogenous groups, and the application of specific interventions tailored for these groups is likely to enhance treatment efficacy (Leboeuf-Yde et al., 1997). It is also well established that LBP is a multi-dimensional problem (Borkan et al., 2002; McCarthy et al., 2004). These dimensions consist of pathoanatomical, neurophysiological, physical and psychosocial factors (Waddell, 2004). To date, the majority of studies that relate to the classification of back pain have focused only on a single dimension of the problem, rather than consideration being given to all dimensions of LBP (Ford et al., 2003). For a classification system to be clinically useful it should be based on identifying the underlying mechanism(s) driving the disorder, in order to guide targeted interventions, which in turn should predict the outcome of the disorder. 2. Models for the diagnosis and classification of CLBP Current approaches or models used for the diagnosis and classification of CLBP have tended to only focus on a single dimension of the disorder, limiting their validity (Ford et al., 2003). The following overview is not designed to be exhaustive, but highlights to the clinician the strengths and weaknesses of these different approaches. 2.1. Patho-anatomical model The traditional medical approach to diagnosis of CLBP has been from a pathoanatomical perspective (Nachemson, 1999). The findings of intervertebral disc (IVD) and facet joint degeneration, annular tears, IVD prolapse, spondylolisthesis, foraminal and spinal stenosis with associated nerve pain are commonly assumed to be related to back pain (and in some cases associated neurogenic pain), with interventions provided on the basis of this assumption (Nachemson, 1999). However, the problem with pathoanatomical diagnoses for CLBP is that many ‘abnormal’ findings are also commonly observed in the pain free population and pathoanatomical findings correlate poorly with levels of pain and disability (Nachemson, 1999). Frequently, little consideration is given to the confounding impact of psycho-social, neuro-physiological and physical factors that may co-exist and contribute to the underlying basis 243 of these disorders (Nachemson, 1999). Because of this, even when a specific pathoanatomical diagnosis can been made, there is still a need to classify the disorder based on the mechanism(s) that drive the pain disorder to ensure appropriate management. 2.2. Peripheral pain generator model More recently there has been a focus on the identification of the painful structure (peripheral pain generator) based on the patient’s history, area of pain, clinical examination findings and diagnostic blocks (Donatelli and Wooden, 1989; Laslett and Williams, 1994; Schwarzer et al., 1994; Bogduk, 1995; Bogduk, 2004). This has led to studies that have reported that the majority of chronic back pain originates in the IVD (45%), with a smaller number of subjects with facet joint (20%) and sacro-iliac joint (15%) pain (Bogduk, 1995). These studies have led to diagnostic and therapeutic procedures to identify, block or denervate the nociceptive source (Bogduk, 2004). The major limitation of this treatment model is that it treats the symptom of pain without consideration for the underlying mechanism or cause of the pain generation, and these approaches frequently only result in short term pain relief and lack broad therapeutic utility (Nachemson, 1999). 2.3. Neuro-physiological model An increased focus on the study of the nervous system and its involvement in pain disorders has documented complex biochemical and neuro-modulation changes at a peripheral, as well as at spinal cord and cortical levels (Flor and Turk, 1984; Flor et al., 1997; Moseley, 2003; Wright and Zusman, 2004). This has highlighted that pain can be generated and maintained at a peripheral level, as well as centrally at both spinal cord and cortical levels. Central sensitisation of pain which is manifest in most CLBP disorders (to varying degrees) can occur secondary to sustained peripheral noniceptive input resulting in changes at spinal cord and cortical levels (Zusman, 2002). This can be both amplified and inhibited by fore-brain descending input (see psychosocial section) (Zusman, 2002). As well as this there is growing evidence that the nervous system undergoes changes to its cortical mapping and possesses a pain ‘memory’ which may leave it pre-sensitized to the exacerbation and recurrence of pain (Zusman, 2002). This new knowledge has lead to an increased focus on medical interventions to inhibit both peripheral and central processing of pain (Bogduk, 2004), as well as psychological and cognitive interventions to reduce the forebrain facilitation of pain (Woby et al., 2004). ARTICLE IN PRESS 244 P. O’Sullivan / Manual Therapy 10 (2005) 242–255 2.4. Psychosocial model The focus on the nervous systems’ role in pain modulation has coincided with increasing research investigating the impact of psychological and social factors on the modulation of pain and in particular, their capacity to increase the central nervous system mediated drive of pain via the forebrain (Linton, 2000; Zusman, 2002; Waddell, 2004). Mal-adaptive coping strategies such as negative thinking, pathological fear and abnormal anxiety regarding pain, avoidant behaviour, catastrophizing and hyper-vigilance have been shown to be associated with high levels of pain, disability and muscle guarding (Frymoyer et al., 1985; Main and Watson, 1996; Nachemson, 1999; Linton, 2000). Social factors such as the compensation system, work place disputes, work and family tensions and cultural issues affecting beliefs reinforce the psychological factors that can increase the central drive of pain (Nachemson, 1999). Despite this advanced knowledge there is debate regarding the relative contribution of these factors to pain disorders and whether these factors predispose, or are as a result of a pain disorder. In contrast positive factors such as adaptive coping strategies, appropriate pacing and distraction (reduced hypervigilance) can have a descending inhibitory effect on pain via the forebrain (Zusman, 2002). Certainly there is evidence that cognitive behavioural interventions are effective in reducing disability in specific groups with non-specific CLBP (Woby et al., 2004), however there appears to be a growing trend within physiotherapy to classify most patients with non-specific CLBP as primarily psychosocial driven due to a lack of an alternative diagnosis. Although all CLBP disorders have psychological and social impact with associated cognitive issues related to the disorder, it appears that only a small sub-group exist where these factors become the dominant or primary pathological basis for the disorder. 2.5. Mechanical loading model Both high and low levels of physical activity are reported to be risk factors for LBP while moderate levels of activity appear protective (Newcomer and Sinaki, 1996; Balague et al., 1999). Mechanical factors are usually reported to be associated with the initial development of LBP and are frequently reported to contribute to the recurrence of LBP and the exacerbation of CLBP. These factors include; sustained low load postures and movements (such as sitting, standing, bending and twisting), exposure to whole body vibration, high loading tasks (such as repeated lifting and bending), as well as sudden and repeated spinal loading in sports specific and manual work situations (Pope and Hansen, 1992; Adams et al., 1999; Nachemson, 1999; Abenhaim et al., 2000; McGill, 2004). These different mechanical exposures are also influenced by ergonomic and environmental factors (McGill, 2004), such as seating design, lifting technique, work place design and sporting equipment. Individual physical factors such as where in its range a spinal articulation is loaded (neutral zone vs. elastic zone), reduced trunk muscle strength and endurance, impaired flexibility, ligamentous laxity and motor control dysfunction as well as anthropometric considerations have also been reported to be associated with LBP (Adams et al., 1999; Abenhaim et al., 2000; McGill, 2004; Dankaerts et al., 2005b; O’Sullivan et al., 2005). Although little direct evidence supports the efficacy of ergonomic interventions for the management of LBP, there is little doubt that physical factors such as sustained end range spinal loading, lifting with flexion and rotation, exposure to vibration and specific sporting activities involving cyclical end range loading of the spine (especially combined with rotation) do negatively impact on the musculo-skeletal system and have the potential to cause ongoing peripheral nociceptor sensitization (Adams et al. 1999; Nachemson, 1999; Abenhaim et al., 2000; Burnett et al., 2004; McGill, 2004). 2.6. Signs and symptoms model The area and nature of pain, impairments in spinal movement and function, changes in segmental spinal mobility (hyper and hypo), as well as pain responses to mechanical stress (provocation tests) and movement (peripheralisation and centralisation of pain with repeated movement) have formed the basis for classifying LBP disorders (McKenzie, 1981; Maitland, 1986; McKenzie, 2000). These approaches are based on biomechanical and pathoanatomical models and have lead to the assessment and treatment of signs and symptoms associated with CLBP (McKenzie, 1981; Maitland, 1986; McKenzie, 2000). Evidence for the efficacy of these approaches for the management of CLBP disorders remains limited (Maher et al., 1999; Abenhaim et al., 2000; Bogduk, 2004). This may in part be due to the limitations of the research design for some of these studies, as well as a neglect to account for the complex biopsychosocial nature of chronic pain disorders (Elvey and O’Sullivan, 2004). 2.7. Motor control model There has been an increased focus on the management of CLBP from a motor control perspective (Richardson and Jull, 1995; O’Sullivan, 1997, 2000; Sahrmann, 2001). While it is well recognized that movement and motor control impairments exist with CLBP disorders, they are highly variable and their presence does not establish cause and effect. Movement and motor control impairments are known to occur secondary to the presence of pain (Hodges and Moseley, 2003; Van-Dieen et al., ARTICLE IN PRESS P. O’Sullivan / Manual Therapy 10 (2005) 242–255 2003). Pathological processes such as neurogenic and radicular pain, neuropathic and centrally mediated pain and inflammatory disorders result in adaptive or protective altered motor behaviour in response to pain (Hall and Elvey, 1999; Elvey and O’Sullivan, 2004). Psychological processes such as stress, fear, anxiety, depression, hysteria, and somatisation are also known to disrupt motor behaviour (Frymoyer et al., 1985; Hodges and Moseley, 2003). Attempts to ‘‘normalize’’ movement or motor control impairments or treat dysfunction in the spinal muscles in many of these disorders would be inappropriate and ineffective due to the nonmechanical basis of these disorders. There is however growing evidence that CLBP disorders do exist where mal-adaptive movement and motor control impairments appear to result in ongoing abnormal tissue loading and mechanically provoked pain (Burnett et al., 2004; Dankaerts et al., 2005b; O’Sullivan et al., 2005). Following an acute episode of low back pain (when tissue healing would have normally occurred), ongoing mal-adaptive motor control behaviour provides a basis for ongoing peripherally driven nociceptor sensitisation leading to a chronic pain state. These disorders are amenable to tailored physiotherapy interventions directed at their specific physical and cognitive impairments (O’Sullivan et al., 1997a–c; Stuge et al., 2004). 2.8. Biopsychosocial model What is clear from the scientific literature and clinical practice, is that a multi-dimensional approach to dealing with CLBP based on a biopsychosocial model is required (Elvey and O’Sullivan, 2004; McCarthy et al., 2004; Waddell, 2004). The relative contribution of the different dimensions and their dominance associated with a CLBP disorder will differ for each patient. The role of the treating clinician is to consider all dimensions of the disorder based on an interview, thorough physical examination (assessing all aspects of the neuromusculosketetal system) combined with review of radiological imaging, medical tests and screening questionnaires (Elvey and O’Sullivan, 2004; O’Sullivan, 2004; Waddell, 2004) (Fig. 1). A clinical reasoning process allows determination of which factors are dominant in the disorder and whether the patient has adapted to the disorder in a positive or negative manner. Consideration of all the factors outlined allows for a diagnosis and mechanism based classification guiding management of the disorder (Elvey and O’Sullivan, 2004) (Fig. 1). 3. Diagnosis and classification of back pain The Quebec task force classification system provides a logical approach for the diagnosis and classification of 245 LBP disorders within a biopsychosocial framework (Spitzer, 1987; Abenhaim et al., 2000; Waddell, 2004). Under this framework red flags are considered in a diagnostic triage. The patient is screened for yellow flags or non-organic features suggestive of psychological and/ or social factors dominating in the disorder. Under this classification system, disorders can be diagnosed as specific (especially nerve root pain) or non-specific, and staged (acute, sub-acute and chronic). 3.1. Diagnosis: specific and non-specific CLBP disorders Specific pathoanatomical diagnoses, although critical for the understanding of many disorders, require further classification. For example, a diagnosis of lumbar spine stenosis (central or foraminal/lateral—chronic stage) may be associated with an adaptive (protective) motor response associated with a functional reduction of the lumbar lordosis with associated lumbar multifidus inhibition, to unload sensitized neural tissue. In this case attempts to normalize the motor control impairments would result in exacerbation and deterioration of the disorder. On the other hand the same diagnosis may be associated with a mal-adaptive motor response, represented by a functional increase in lumbar lordosis with associated back muscle guarding, resulting in further neural compromise and direct aggravation of the disorder. In this case normalising the motor control impairments (to functionally reduce the lumbar lordosis) would be indicated and effective. This proposed classification (into adaptive/mal-adaptive motor control responses) directly influences whether the patients’ specific disorder is amenable for physiotherapy management that is aimed at normalising the motor control impairments or not. Alternatively, this diagnosis may be associated with a dominance of psychosocial factors and associated dominant central nervous system sensitisation, compromising the potential success of both conservative physiotherapy and surgical interventions. In this case the same specific diagnosis may present with a different classification, reflecting a different underlying pain mechanism and therefore indicating a different intervention (Elvey and O’Sullivan, 2004). Eighty-five percent of CLBP disorders do not have a specific diagnosis (Dillingham, 1995). These disorders are labelled ‘non-specific CLBP’ disorders and represent a large group of ‘tissue strains’ and ‘sprains’ that have not resolved beyond normal tissue healing time (Abenhaim et al., 2000). This group has been broadly classified based on the area of pain and defined as somatic referred or radicular in nature (Abenhaim et al., 2000). However this diagnostic/classification system is of limited clinical value as it does not identify the underlying mechanism driving the pain disorder, and consequently there is no clear direction for specific management (Padfield and Butler, 2002). ARTICLE IN PRESS P. O’Sullivan / Manual Therapy 10 (2005) 242–255 246 Social factors - relationships – family, friends, work - work structure - medical advice - support structures - compensation – emotional, financial - cultural factors - socio-economic factors Genetic factors Patho-anatomical factors - potentially influencing all other domains - structural pathology - identify peripheral pain generator (IVD / Zt joint / SI Jt / neural tissue / myo-fascial / connective tissue) Physical factors Psychological factors - personality type - beliefs & attitudes - hypervigilance - coping strategies – confronter vs avoider - pacing - emotions - fear / anxiety / depression / anger - iIlness behaviour Pain Neuro-physiological factors - peripheral sensitisation - central sensitisation - sympathetic nervous system activity - somatic complaints - ‘passive’ structure competence (hypermobility) - developmental factors - mechanism of injury - disorder history and stage - area of pain – local / generalised / referred - pain behaviour – directional / centralisation - mechanical vs non-mechanical provocation - articular mobility - neural tissue provocation testing - neurological examination - motor control / myo-fascial considerations - adaptive vs mal-adaptive motor response - movement impairments (directional) - motor control impairments (directional) - activity levels / conditioning / strength / muscle endurance - work / home environment / lifestyle - ergonomic factors Fig. 1. Factors that need consideration within a biopsychosocial framework, for the diagnosis and classification of CLBP disorders. 3.2. Classification of CLBP Due to the shortcomings of the current models, it is clear that both specific and non-specific CLBP disorders require further classification based on a biopsychosocial construct. There are a number of key clinical indicators regarding pain area and behaviour, which provide an important insight into the different mechanisms underlying and driving a pain disorder, allowing classification to be made. Considered simplistically, the presence of localized and anatomically defined pain associated with specific and consistent mechanical aggravating and easing factors, suggest that physical/mechanical factors are likely to dominate the disorder resulting in a primary peripheral nociceptive drive. Correlation between clinical examination and pathoanatomical findings is critical to determine their significance and relationship to the disorder. If pain is constant, non-remitting, widespread and is not greatly influenced by mechanical factors (or minor mechanical factors result in an exaggerated and disproportionate pain response), then inflammatory or centrally driven neurophysiological factors (such as altered central pain processing) are likely to dominate the disorder. High levels of anxiety, hypervigilance, fear and emotional stress presenting as primary aggravating or precipitating factors in the disorder, highlight the influence of psychological and in some cases social factors indicating the dominant forebrain drive of pain in a disorder (Linton, 2000). Understanding a patient’s social circumstances, work environment, lifestyle factors and beliefs regarding their disorder is also critical (Waddell, 2004). Whether the patient has active or passive coping strategies in managing their disorder, and whether they pace themselves is important in understanding their capacity to actively manage their pain (Bergstrom et al., 2001). In reality most disorders will be associated with a combination of these factors, and the role of the clinician is to consider the balance and dominance of them in the disorder (Fig. 1). It is proposed that there are three broad sub-groups of patients that present with disabling CLBP associated with movement and control impairments (Fig. 4). (1) The first sub-group is represented by disorders where high levels of pain and disability, as well as movement and/or control impairments are secondary and adaptive to an underlying pathological process. These include red flag disorders, specific pathoanatomical disorders in some circumstances (such as IVD prolapse, spinal and foraminal stenosis with associated radicular pain 7 neurological deficits, internal disc disruption with associated inflammatory pain, ‘unstable’ grade 2–4 spondylolisthesis), inflammatory pain disorders, neuropathic and centrally or sympathetically mediated pain disorders. These patients present with antalgic movement patterns and altered motor control that is driven directly by the pain disorder. The therapist will quickly determine this as attempts to ‘normalize’ these motor control and movement impairments results in exacerbation or non-resolution of the disorder, as these impairments are adaptive and driven by pathological processes. If the pathological process resolves with time or secondary to specifically targeted interventions (i.e. appropriate medical and/or surgical management when indicated), the signs and symptoms (e.g. motor ARTICLE IN PRESS P. O’Sullivan / Manual Therapy 10 (2005) 242–255 control and movement impairments) related to the disorder resolve. Specifically targeted therapy management may be indicated for some of these disorders in conjunction with other primary medical interventions with full knowledge of the non-mechanical underlying basis of the disorder (Elvey and O’Sullivan, 2004). These disorders represent a small but severely disabled group within the CLBP population. (2) A second small sub-group exists where the drive of the pain disorder is from the forebrain, secondary to a dominance of psychological and/or social (non-organic) factors. Although psychological and social impact occurs with all chronic disabling pain disorders, it appears that for a small group of patients it represents the dominant central drive of their disorder. This results in high levels of disability, altered central pain processing, amplified non-remitting pain, and resultant disordered movement and motor control impairments. These disorders commonly present with dominant psycho-social features, including pathological anxiety, fear, anger, depression, negative beliefs, un-resolved emotional issues, poor coping strategies (lack of pacing resulting in pain provocation or excessive avoidance of activity as means of controlling pain) as well as negative social and inter-personal circumstances (Linton, 2000; Bergstrom et al., 2001; Waddell, 2004). These psychological and social stresses present as dominant coexisting, precipitating and primary aggravating factors for the disorder (Linton, 2000). The key feature of these disorders is the absence of an organic basis to the disorder, and lack of clear and consistent mechanical provocation or relieving patterns (absence of peripheral nociceptor drive). When mechanical factors are provocative they are inconsistent and tend to result in abnormal and disproportionate pain, disability and emotional responses. These patients commonly present with high levels of dependence on strong analgesic medication and passive forms of health care provision by multiple practitioners, even though they report a poor response to these interventions (Waddell, 2004). It is important to note that a therapist should not arrive at this classification without consultation and confirmation by either a treating clinical psychologist or psychiatrist. In this sub-group, attempts to simply treat the ‘signs and symptoms’ of the disorder directly (e.g. movement and control impairments) does not result in their resolution, as the underlying mechanism driving the pain is not addressed. Management of these disorders requires multi-disciplinary management with a primary focus on cognitive behavioural therapy (Bergstrom et al., 2001) and psychiatric management. Physiotherapy management can play a specialized role in reinforcing graded functional recovery while reducing the focus on pain, however it cannot be seen as the primary treatment for these disorders (Elvey and O’Sullivan, 2004). 247 (3) It is proposed that a large third sub-group exists where mal-adaptive movement or control impairments and associated faulty coping strategies result in chronic abnormal tissue loading (associated with either excessive or reduced spinal stability), pain, disability and distress. This group is classified on the basis that the ‘movement’ impairments (characterized by pain avoidance behaviour) or ‘control’ impairments (characterized by pain provocation behaviour) act as the underlying mechanism that drives the CLBP state. Normalisation of the movement or control impairments based on a cognitive behavioural approach results in resolution and/or control of these disorders. Disorders with a ‘movement’ and ‘control’ impairment classification present commonly in clinical practice, and they appear to have different underlying pain mechanisms from each other and therefore their management is distinctly different (Figs. 2 and 3). These disorders may present as specific (associated with a pathoanatomical diagnosis) or nonspecific CLBP disorders, and are commonly associated with psychological, social, neurophysiological (central sensitisation) factors, that may contribute to but do not dominate or drive the disorder. The classification of these disorders leaves them amenable to therapy intervention directed at the primary physical (movement and control) impairments while addressing the secondary cognitive aspects of the disorder (see Fig. 4). 3.2.1. Movement impairment classification CLBP disorders classified as ‘movement impairment’ present with a painful loss or impairment of normal (active and passive) physiological movement in one or more directions (Figs. 2, 3 and 5a). These disorders are associated with abnormally high levels of muscle guarding and co-contraction of lumbo-pelvic muscles when moving into the painful and impaired range. This appears to be driven by an exaggerated withdrawal motor response to pain. This leads to high levels of compressive loading across articulations, movement restriction and rigidity (excessive stability), resulting in a mechanism for tissue strain and ongoing peripheral nociceptor sensitisation. These patients are usually acutely aware of their pain and are fearful of moving into the painful movement direction as they perceive that pain provocation is damaging. The fear of movement appears to develop from the patients’ initial experience of severe acute pain, as well as their beliefs (reinforced by sympathetic family members and treatment providers) that pain is harmful. Movement related fear, hyper-vigilance and anxiety associated with the pain reinforces the faulty cognitive coping strategies and beliefs, further amplifying the pain centrally and reinforcing their muscle guarding. This represents a mal-adaptive response to the pain disorder, as the compensations for the pain in turn becomes the mechanism that drives the disorder. These disorders ARTICLE IN PRESS 248 P. O’Sullivan / Manual Therapy 10 (2005) 242–255 (A) Movement impairment classification Nature and mechanism of pain: Localised pain +/- referral Severe pain of rapid onset Movement impairment in direction of pain Hyper-awareness of pain Exaggerated reflex withdrawal motor response Muscle guarding and abnormal tissue loading (↑spinal stability) Avoidance of movement into painful range Disability Directional (flexion, extension, rotation, lateral shift, loading) Multi-directional Result: Peripheral pain sensitisation (B) Control impairment classification Nature and mechanism of pain: Localised pain +/- referral Gradual onset of pain from repeated or sustained strain No impaired movement in direction of pain Lack of awareness of pain triggers Poor lumbo-pelvic position sense Absence of reflex withdrawal motor response Ongoing tissue strain (↑or↓ spinal stability) Provocation into painful range Avoidance of painful activity Disability Directional (flexion, extension, rotation, lateral shift, loading) Multi-directional Result: Peripheral pain sensitisation Anxiety related to movement pain Fear avoidance when moving in direction of pain (pathological) Hyper-vigilence Belief that pain is damaging (pathological) Anxiety related to chronic disabling pain Fear of activity (non-pathological) Lack of control and awareness of disorder Belief that activity is damaging (non-pathological) Result: Central pain sensitisation Result: Central pain sensitisation Normalisation of movement impairment leads to resolution / control of disorder Normalisation of control impairment leads to resolution / control of disorder Fig. 2. The nature and mechanism associated with mal-adaptive motor control disorders with: (A) Movement impairment classification and (B) control impairment classification (italics represent common features of the disorders / normal text highlights differences between the disorders). may present in a directional manner (flexion, extension, side bending and rotational impairments) as well as combinations of these movements (multi-directional movement impairments). Management of this patient sub-group is directed at both the dominant physical and associated cognitive factors that underlie the disorder. The aim is first to educate the patient that their pain is not damaging and they have developed faulty compensations to their pain, which now act to maintain their disorder. Restoration of the painful impaired movement is critical for the resolution of the disorder. The aim of the intervention is to desensitize the nervous system by restoring normal movement, reducing the fear of movement into pain and associated muscle guarding. This is facilitated by graded movement exposure into the painful range in a relaxed and normal manner based on the individual patient presentation. The cognitive strategies of reducing fear and changing beliefs regarding pain is augmented by manual therapy ‘treatment’ to restore the movement impairment (articular mobilisation/manipulation and soft tissue techniques). This is combined with active ‘management’ approaches directed to restore the movement impairment (muscle relaxation, breathing control, postural adjustments, graded movement exposure ex- ercises, cardio-vascular exercise and most importantly graded functional restoration to normalize motor control). As the movement impairment and associated movement-based fear reduces, so too does the disability and pain related to the disorder. Stabilising exercise programs and treatment approaches that focus on pain and reinforce the avoidance behaviour usually exacerbate these disorders and are contra-indicated. 3.2.1.1. Case study 1. A 28-year-old woman reported a 3 year history of disabling non-specific CLBP (central lower lumbar) that had developed following a lifting injury while working as a nurse. She was placed off work for three weeks and was told by her physiotherapist that she had injured her disc, should do ‘McKenzie extension exercises’, avoid flexion and maintain her lumbar lordosis at all times. She reported becoming disabled with pain and very fearful of bending her back which she avoided doing from that time. Her treatment history consisted of McKenzie extension exercises, Pilates, stabilisation training (with a focus on pelvic floor, transverse abdominal wall and lumbar multifidus co-activation) and swimming. She had seen an orthopaedic surgeon, pain specialist, clinical psychologist, a number of physiotherapists and was taking ARTICLE IN PRESS P. O’Sullivan / Manual Therapy 10 (2005) 242–255 Mal-adaptive CLBP disorders -where ‘movement’ and ‘control’ impairments …. dominate and represent underlying mechanism for pain Tissue injury / localised pain Motor response Movement impairment classification Factors that may influence pain and motor response physical patho-anatomical genetic neuro-physiological motor control psycho-social coping strategies beliefs fear avoidance compensation - segmental spinal - directional / multi-directional Management Non resolution mal-adaptive patterns adopted poor coping strategies NMS response prolonged excessive↔reduced spinal stability abnormal tissue loading peripheral / central sensitisation Resolution of the disorder - education – regarding pain mechanism - reduce fear - cognitive behavioural approach - restore movement impairment - graded movement restoration - graded pain exposure - functional restoration - normalise movement behaviour Control impairment classification - segmental spinal - directional / multi-directional Management - education – regarding pain mechanism - cognitive behavioural motor control intervention - pain control (avoid provocation) - retrain faulty postures and movements - self control of pain - functional restoration - normalise movement behaviour Fig. 3. Mal-adaptive motor control impairment CLBP disorders. CLBP disorders associated with altered motor control Adaptive / protective altered motor response to an underlying disorder - inflammatory disorders - centrally mediated pain - sympathetically maintained pain - neurogenic pain - neuropathic pain Altered motor response and centrally mediated pain secondary to dominant psychosocial factors Mal-adaptive motor control patterns that drive the pain disorder - movement impairments - control impairments (may result in an excess or loss of spinal stability) Fig. 4. Altered motor responses in the presence of CLBP (3 groups). 249 ARTICLE IN PRESS 250 P. O’Sullivan / Manual Therapy 10 (2005) 242–255 8/10, her disability index (Oswestry disability index) was 40% and she had high levels of kinesiophobia (Tampa scale of Kinesiaphobia). Investigations: Physical examination Observation X-rays/MRI Lumbar spine— NAD she sat and walked with a rigid erect thoraco-lumbar spine posture she sat forward on the chair with a lordotic spinal posture she maintained thoracolumbar lordosis and avoided flexion when moving from sitting to standing and while undressing AROM Fig. 5. (a) Patient with classification of movement impairment into flexion (note the pain provocation into flexion is associated with an impairment of lumbar spine flexion). (b) Patient with classification of control impairment into flexion (note the pain provocation into flexion is not associated with an impairment of lumbar spinal flexion). anti-depressants, strong analgesic and muscle relaxant medication. She was only able to work 2 days per week doing light duties because of her CLBP disorder. She reported that her symptoms were exacerbated by all flexion postures and movements such as slump sitting, bending, dressing and lifting activities. Extension related spinal movements such as standing and walking were pain free. She gained relief from her pain with heat and rest. She reported high levels of anxiety relating to pain, disability and an inability to work full time. She constantly worried about her back pain and believed that she would not get better as she had a disc injury that had not resolved. She coped with her back pain by avoiding provoking it and restricting her activities involving spinal flexion. Her pain intensity level was Flexion—hip flexion 501, no thoraco-lumbar flexion with use of hands to support her and assist her return to upright (Fig. 5a) Extension—301 no pain Side bending—full ROM and pain free Repeated flexion increased guarding and report of pain Motion palpation L5/S1—hypo-mobile in flexion Provocation palpation of L4 and L5 centrally— reproduced pain (highly sensitized) SIJ NAD Neural provocation NAD tests Motor control 1. Functional movement tests—stated under observation 2. Specific movement testing—attempts to posteriorly rotate pelvis in sitting, supine and four point kneeling were associated with pain and muscle guarding. 3. Specific muscle testing—able to isolate co-activation of the transverse abdominal wall and lower lumbar multifidus in neutral lordosis (difficulty observed relaxing them). Diagnosis Classification non-specific CLBP Movement impairment disorder–flexion pattern L5/S1 The disorder diagnosis of non-specific CLBP was based upon the non-resolution of a flexion back sprain and the absence of a specific diagnosis. The disorder classification of this patient was a movement impairment disorder (into flexion with localized pain at L5/S1). ARTICLE IN PRESS P. O’Sullivan / Manual Therapy 10 (2005) 242–255 The mechanism underlying the pain is a movement impairment with a loss of normal physiological movement into flexion, with associated muscle guarding and fear of forward bending. This movement impairment and associated fear was initiated in the acute phase and was reinforced by her beliefs that pain associated with flexion of her spine was damaging for her. This patient avoided bending due to the knowledge that flexion will provoke pain and the belief (reinforced by treatment providers) that this movement causes ‘further damage’ and that by not moving into this painful direction will prevent damage. The basis of this pain disorder is linked to both dominant peripheral and secondary central pain mechanisms. Management of this patient was directed at both the dominant peripheral and secondary central mechanisms of the pain disorder over a 12 week period. Management first focussed on educating the patient regarding the basis and mechanism of her disorder. It was critical to change the patient’s beliefs, so that she understood that to relax the spinal muscles and restore normal movement in the direction of her pain was essential for resolution of the pain disorder. The patient was assured that her movement-provoked pain into flexion was not dangerous or damaging. The restoration of normal tissue compliance and reduction of muscle guarding was facilitated by ‘passive’ treatment techniques directed to restore flexion mobility to the lower lumbar spine (L5/S1 flexion articular mobilisation techniques and soft tissue inhibitory techniques directed to her back extensor and psoas muscles). This was combined with graded active movement into the restored range. This involved the patient initially being taught to posteriorly tilt her pelvis in a relaxed manner without trunk muscle guarding and breath holding (initially in supine and four point kneeling progressed to sitting and standing). She was instructed to cease cognitively contracting her spinal ‘stabilising muscles’ but rather to relax her upright postures so to reduce her thoracolumbar hyper-lordosis to a neutral spine posture. Finally the patient was trained to flex her spine in upright postures (sitting and standing) in a normal physiological manner without guarding. As the movement impairment was restored, the pain, disability and fear of bending also reduced. At this stage the patient reported that she had the capacity to control her pain. This new control was then introduced into previously provocative functional tasks such as dressing and housework. She reported that she could work longer and increase her general activity levels. She was encouraged to carry out regular cardio-vascular exercise and join a yoga class to maintain her spine mobility in a relaxed manner. The resolution of her CLBP disorder supported the classification and management approach taken. 251 3.3.1. Control impairment classification CLBP disorders classified as ‘control impairment’ appear to be most common in clinical practice. These disorders are associated with impairment or deficits in the control of the symptomatic spinal segment in the primary direction of pain. In these disorders there is no movement impairment in the direction of pain (Figs. 3 and 5b). Pain in these disorders is associated with a loss of functional control around the neutral zone of the spinal motion segment due to specific motor control deficits (and muscle guarding in some situations) of the spinal stabilising muscles. This is manifest during dynamic and/or static tasks as 1. ‘through range movement pain’ due to non-physiological motion of the spinal segment observed during dynamic tasks, 2. ‘loading pain’ due to non-physiological loading of the spinal segment (not end range) observed during static loading tasks and 3. ‘end of range pain’ or ‘overstrain’ due to repetitive strain of the spinal motion segment at the end of range observed during static and dynamic functional tasks. The irony with these patients is that they adopt postures and movement patterns that maximally stress their pain sensitive tissue (Burnett et al., 2004; O’Sullivan et al., 2004; Dankaerts et al., 2005b), and yet they have no awareness that they do this. One reason for this may relate to the fact that their pain is often of a gradual onset and therefore they lack a withdrawal reflex motor response, coupled with a lack of proprioceptive awareness of the lumbo-pelvic region (Fig. 2) (O’Sullivan et al., 2003; Burnett et al., 2004). This control deficit is clearly mal-adaptive and represents a powerful mechanism for ongoing pain (which is both peripherally and centrally mediated) and disability. These patients present with movement based fear that is real, as their movement strategies are highly provocative of their pain disorder, resulting in failure to respond to general exercise and conditioning interventions. These disorders frequently present in a directional manner (flexion, extension (passive or active) and lateral shift control impairment) as well as combinations of these directions (multi-directional control impairment). These disorders may be associated with deficits in the spinal stabilising muscles (i.e. flexion pattern) or excessive muscle activity resulting in increased spinal loading (i.e. active extension pattern). These directional patterns are described in detail elsewhere (O’Sullivan, 2000, 2004). Clinical instability of the lumbar spine represents a sub-group of these disorders (O’Sullivan, 2000, 2004). Management of this sub-group is based on a cognitive behavioural motor learning intervention model. This intervention is based on the premise that mal-adaptive ARTICLE IN PRESS 252 P. O’Sullivan / Manual Therapy 10 (2005) 242–255 motor control behaviour provides an ongoing mechanism for tissue strain and peripheral nociceptive drive. The aim of the intervention is to desensitize the nervous system by educating the patient to control their pain provocative postures and movement patterns so as to avoid repetitive strain on the painful tissue, reduce the peripheral nociceptive drive and in turn enhance function. This is not simply an exercise program rather it follows a motor learning intervention model with the aim of changing movement behaviour via physical as well as cognitive learning processes. As the motor control is enhanced, the repeated stress on the symptomatic tissue reduces, resulting in less peripheral nociceptive drive into the nervous system, allowing the pain disorder to resolve. This provides the patient with the capacity to manage their disorder in an effective manner, which reduces their fear of activity and increase their levels of function. This intervention directly impacts on both the dominant peripheral nociceptive as well as the secondary central drives for the pain disorder. The role of manual therapy treatment in control impairment disorders is limited only to the restoration of articular movement away from the direction of pain provocation and only if this movement is impaired and inhibiting the muscle synergies controlling this movement. These techniques are never used in isolation, but rather they facilitate movement so as to enhance the restoration of motor control to dynamically unload the pain sensitive tissue. For example in a flexion pattern control impairment disorder, if a loss of segmental spinal extension prohibits restoring control over the lower lumbar lordosis, then manual therapy treatment may be used to facilitate extension. This is immediately followed by training active control over this movement so as to reduce the flexion load of the motion segment. The specifics of this intervention have been reported in detail previously (O’Sullivan, 2000, 2004). 3.3.1.1. Case study 2. A 42-year-old male reports a 2 year history of non-specific CLBP. He first developed central LBP while lifting (with a flexed lumbar spine) a 30 kg bag of fertilizer while working as a labourer. His back pain disorder did not resolve and he had not been able to return to work. His previous treatment consisted of physiotherapy, Pilates, gym based exercise programs, psychological intervention and medication (strong analgesics and antidepressants). He reported that his back pain was provoked by static flexed spinal postures (sitting, driving, semi-inclined bending) and activities (such as lifting, sit—stand, dressing). He reported that he avoided all such activities as they exacerbated his pain and it took days then to settle. He reported relief with extension or lordotic postures. He reported feeling depressed due to the nature of his disability, his loss of independence and his alienation with his health providers, work and family and was tearful when describing this. He was also limited in his ability to socialize with his friends. He had been told there was nothing structurally wrong with his back and that he would have to learn to live with his problem and he believed that his condition was unlikely to improve. His pain intensity level was 7/10, his disability index (Oswestry disability index) was 42% and he had high levels of kinesiophobia (Tampa scale). Physical examination Observation he sat down to undress, and used his hands to assist transferring from sitting to standing AROM Flexion—no lower lumbar movement impairment (full low lumbar ROM) into flexion with report of LBP mid range (Fig.5b) Extension—301 no pain Right and left side bending—full ROM Repeated and sustained spinal flexion increased his LBP PPIVM L5/S1—hyper-mobile in flexion Provocation palpation of L5/S1 central—painful with reproduction of back pain Neural NAD provocation tests Motor control: 1. Functional movement tests—forward bending, reaching, lifting, sit to stand and squatting were associated with increased flexion at the lower lumbar spine, a loss of anterior pelvic rotation and lordosis in the upper lumbar and thoracic spine (Fig. 4b). The use of the arms was observed to support the trunk with these activities. 2. Specific movement tests—Attempts to initiate anterior pelvic tilt and extend the lower lumbar spine in standing, sitting and supine were associated with upper lumbar and thoracic spine extension 3. Specific muscle testing—Inability to isolate the activation of the pelvic floor, transverse abdominal muscles and lumbar multifidus with posterior pelvic rotation and flexion of the lower lumbar spine, with bracing of the upper abdominal wall. Investigations Diagnosis Classification X-rays/MRI lumbar spine— degenerative disc disease L5/S1 (mild) non-specific CLBP control impairment disorder— flexion pattern at L5/S1 ARTICLE IN PRESS P. O’Sullivan / Manual Therapy 10 (2005) 242–255 The diagnosis of non-specific CLBP was based on the non-resolution of a flexion back sprain beyond normal healing time and the lack of a specific diagnosis. The classification of this patient as control impairment disorder (flexion pattern) is based on the underlying mechanism of this pain disorder being directly linked to an ongoing flexion strain of the L5/S1 motion segment secondary to a loss of functional control of the segment into flexion. The patients’ sense of alienation, frustration, anger and depression further confounds his situation resulting in increased central drive of his pain. Management of this patient was directed on a cognitive behavioural motor learning frame-work (O’Sullivan, 2004). The patient was first educated that subsequent to his initial back sprain he had adopted a mal-adaptive motor control pattern that exposed the symptomatic segment to abnormal and repetitive strain into flexion, which in turn maintained his pain. This was further reinforced by his anxiety levels related to work and home, lack of control over his pain disorder and inactivity. Management focused on a motor control intervention to reduce the flexion strain at L5/S1 in a functionally specific manner with relaxation of the thoraco-lumbar spine and enhancing control of segmental lordosis at L5/S1. Initally he was taught to dis-associate lumbo-pelvic lordosis from thoracic in supine, sitting and standing. This was in order to develop proprioceptive awareness and control of this region and so reduce the flexion strain at L5/S1. Once this was achieved he was then taught to coactivate his lower lumbar multifidus with his transverse abdominal wall (in a neutral lordosis), with relaxation of his thoracic erector spinae and upper abdominal muscles (with normal respiration) in these postures. At this stage previously aggravating postures and movements into forward bending were targeted and retrained so that the patient could perform them (controlling the L5/S1 within a neutral lordosis), in a pain-free manner thereby enhancing his functional capacity. This in turn reduced his fear of movement and activity. His exercise program was then progressed into a gym setting where he was taught to integrate his lumbo-pelvic control into a graded cardiovascular exercise program as well as training strength and endurance with loaded tasks such as squats, lunges and resistance lifting tasks. As the patient’s functional mobility increased and pain reduced his coping strategies improved and he was capable of a graduated return to work. The resolution of the disorder supports the classification that the control impairment into flexion represented the dominant underlying mechanism driving the disorder. 4. Validity of the classification system There is a growing concensus within the literature that current diagnostic and classification approaches for 253 CLBP are limited, and a mechanism based classification of CLBP disorders from a biopsychosocial perspective is required (McCarthy et al., 2004). Although considerable research has documented the biopsychosocial nature of CLBP, further research is required to test the validity of this approach in management of CLBP disorders to determine whether it predicts and indeed improves patient outcomes. There is growing evidence to support the validity of the ‘control impairment’ classification system as a subgroup with CLBP. Recent research has shown that physiotherapists trained in the classification system can reliably identify five different subgroups with a classification of control impairment (Dankaerts et al., 2005a, b). Laboratory evidence for the presence of specific motor control and postural deficits have been documented in a series of studies conducted on patients with CLBP with a classification of ‘control impairments’ (O’Sullivan et al., 1997a–c, 2003; Burnett et al., 2004; O’Sullivan et al., 2004; Dankaerts et al., 2005b). Motor learning interventions have been shown efficacious in patient groups with a classification of control impairment, with documented reductions in pain and disability (O’Sullivan et al., 1997a–c, 1998, 2001; Dankaerts et al., 2004). 5. Summary CLBP disorders must be considered within a biopsychosocial framework. The presence and dominance of the potential pathoanatomical, physical, neurophysiological, psychological and social factors that may impact on these disorders is different for each individual with CLBP. This highlights the enormous complexity and individual nature of the problem. It is critical that classification of CLBP pain disorders be based on the mechanism (s) underlying and driving the disorder. It is proposed that motor control impairments may be adaptive or mal-adaptive in nature. The treatment of the signs and symptoms of a pain disorder cannot be justified without an understanding of its underlying mechanism as there are sub-groups of patients for whom physiotherapy treatment is not indicated. It is proposed that there is a large sub-group of CLBP disorders where mal-adaptive movement and control impairments dominate the disorder, resulting in either excessive or impaired dynamic spinal stability and loading. This in turn becomes a mechanism for ongoing pain. 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Wright A, Zusman M. Neurophysiology of pain and pain modulation. In: Modern Manual Therapy, Boyling and Jull. 3rd ed. Amsterdam: Elsevier; 2004. Zusman M. Forebrain-mediated sensitization of central pain pathways: ‘non-specific’ pain and a new image for MT. Manual Therapy 2002;7(2):80–8. TITLE: Diagnosis and classification of pelvic girdle pain disorders Part 1: A mechanism based approach within a biopsychosocial framework. AUTHORS: Ass Prof Peter B. O’Sullivan, PhD Curtin University of Technology School of Physiotherapy Darren J. Beales, Master of Manipulative Therapy Curtin University of Technology School of Physiotherapy CORRESPONDANCE: Ass Prof Peter O’Sullivan Curtin University of Technology School of Physiotherapy GPO Box U1987 Perth WA Australia 6845 Phone: 61 8 9266 3629 Fax: 61 8 9266 3699 E-mail: [email protected] INSTITUTIONAL ATTRIBUTION: As above KEY WORDS: pelvic girdle pain, sacroiliac joint, classification, pain mechanisms ABSTRACT: The diagnosis and classification of pelvic girdle pain (PGP) disorders remains controversial despite a proliferation of research into this field. The majority of PGP disorders have no identified pathoanatomical basis leaving a management vacuum. Diagnostic and treatment paradigms for PGP disorders exist although many of these approaches have limited validity and are uni-dimensional (ie. biomechanical) in nature. Furthermore single approaches for the management of PGP fail to benefit all. This highlights the possibility that ‘non-specific’ PGP disorders are represented by a number of sub-groups with different underlying pain mechanisms rather a single entity. This paper examines the current knowledge and challenges some of the common beliefs regarding the sacroiliac joints and pelvic function. A hypothetical ‘mechanism based’ classification system for PGP, based within a biopsychosocial framework is proposed. This has developed from a synthesis of the current evidence combined with the clinical observations of the authors. It recognises the presence of both specific and non-specific musculoskeletal PGP disorders. It acknowledges the complex and multifactorial nature of chronic PGP disorders and the potential of both the peripheral and central nervous system to promote and modulate pain. It is proposed that there is a large group of predominantly peripherally mediated PGP disorders which are associated with either ‘reduced’ or ‘excessive’ force closure of the pelvis, resulting in abnormal stresses on pain sensitive pelvic structures. It acknowledges that the interaction of psychosocial factors (such as passive coping strategies, faulty beliefs, anxiety and depression) in these pain disorders has the potential to promote pain and disability. It also acknowledges the complex interaction that hormonal factors may play in these pain disorders. This classification model is flexible and helps guide appropriate management of these disorders within a biopsychosocial framework. While the validity of this approach is emerging, further research is required. TEXT: PELVIC GIRDLE PAIN DISORDERS Pelvic girdle pain (PGP) disorders represent a small group of musculoskeletal pain disorders. Pain associated with the sacroiliac joints (SIJ’s) and/or the surrounding musculoskeletal and ligamentous structures represent a sub-group of these disorders. Specific inflammatory pain disorders of the SIJ’s, such as sacroiliitis, are the most readily identified PGP disorders (Maksymowych et al., 2005). However PGP disorders more commonly present as ‘non-specific’ (no identified pathoanatomical basis), often arising during or shortly after pregnancy (Bastiaanssen et al., 2005; Berg et al., 1988; Ostgaard et al., 1991) or following traumatic injury to the pelvis (Chou et al., 2004; O'Sullivan et al., 2002a). Frequently these pain disorders are misdiagnosed and managed as lumbar spine disorders, as pain originating from lumbar spine commonly refers to the SIJ region. However there is growing evidence that PGP disorders manifest as a separate sub-group with a unique clinical presentation and the need for specific management. A number of PGP disorders do not resolve (Albert et al., 2001; Larsen et al., 1999; Noren et al., 2002; Ostgaard et al., 1996; To and Wong, 2003), becoming chronic despite the absence of pathoanatomical abnormalities on radiological examination or signs of a systemic or inflammatory disorder from blood screening (Hansen et al., 2005). This leads to a broad diagnosis of a ‘non-specific’ PGP disorder and leaves a diagnostic and management vacuum. These PGP disorders are commonly associated with signs and symptoms indicating that the pain originates from the SIJ’s and/or their surrounding connective tissue and myo-fascial structures (Albert et al., 2000; Berg et al., 1988; Damen et al., 2001; Kristiansson and Svardsudd, 1996; Laslett et al., 2003; Mens et al., 1999; O'Sullivan et al., 2002a; Vleeming et al., 2002). However identification of a painful structure does not provide insight into the underlying mechanism(s) that drives the pain (O'Sullivan, 2005a). A number of theoretical models have been proposed with regard to potential underlying pain mechanisms in PGP. Chiropractic, Osteopathic and Manual Therapy models commonly propose that the SIJ’s can become ‘fixated’ or ‘displaced’ leading to positional faults. There are a series of complex clinical procedures proposed to identify these so called ‘positional faults’ and treatment with manipulation, mobilisation and/or muscle energy techniques has been suggested to rectify them (Cibulka, 2002; DonTigny, 1990; Kuchera, 1997; Oldreive, 1998; Sandler, 1996). Although manual and manipulative techniques can result in short term pain modulation (Wright, 1995), there is little evidence for the long term benefits of SIJ manipulation or other passive treatments used in isolation for the management of chronic PGP disorders (Stuge et al., 2003). The selection of these techniques is often directed by treating the signs and symptoms of the disorder rather than a valid and clear diagnostic and classification paradigm based on the mechanisms that underlie the pain disorder. More recently emphasis has been placed on enhancing motor control deficits in PGP disorders. This is based on the premise that deficits in lumbo-pelvic motor control result in impaired load transference through the pelvis and thereby contribute to a peripheral nociceptive drive of symptoms (Mens et al., 1996; O'Sullivan and Beales, 2007; O'Sullivan et al., 2002a; Vleeming et al., 1996; Vleeming et al., 1990b). There is growing evidence based on outcome studies that some PGP disorders do indeed respond well to specifically targeted motor training interventions (O'Sullivan and Beales, 2007; Stuge et al., 2004a; Stuge et al., 2004b). However not all PGP disorders respond to these interventions (Stuge et al., 2006). Relevant to this inconsistency in outcome, is the existence of different patterns of motor control impairments in PGP subjects. For instance increased pelvic floor activation has been documented in subjects with peripartum PGP consistent with SIJ involvement (Pool-Goudzwaard et al., 2005), while another group of subjects with SIJ pain (with a positive active straight leg raise test (ASLR)) demonstrate compromised control of the pelvic floor (O'Sullivan and Beales, 2007; O'Sullivan et al., 2002a). These findings highlight that; (i) there may be various underlying mechanisms that drive different PGP disorders, and (ii) the need for a classification based approach which guides targeted interventions for sub-groups of subjects with PGP, which is based upon the underlying pain mechanism(s) that drives the disorder. CHALLENGING THE BELIEFS REGARDING THE SACROILIAC JOINTS AND THE PELVIS The SIJ perhaps more than any other joint complex in the body has been shrouded by an enormous amount of mystique within the field of Manual Therapy – with complex, poorly validated and often confusing theories and treatment approaches associated with it. Beliefs of the clinician (that the pelvis is ‘displaced’ or ‘unstable’) commonly become the beliefs of the patients. For many patients these clinical labels can be detrimental with the potential to render the patient passively dependent on someone to ‘fix them’, elevating anxiety levels, reinforcing avoidance behaviours and promoting disability. Increased passive dependence and fear/anxiety has the potential to further increase the central drive of pain, contributing to disability and the chronic pain cycle. It is therefore important to be clear on the ‘facts’ regarding the SIJ’s and put them into the context of current knowledge. The basic anatomy, biomechanics and stability models proposed for the SIJ are documented elsewhere and as such wont be reviewed in full here (Lee and Vleeming, 2000; Pool-Goudzwaard et al., 1998; Vleeming et al., 2006). The facts regarding the SIJ’s • The SIJ’s are inherently stable (Snijders et al., 1993a; Vleeming et al., 1990a; Vleeming et al., 1990b). • The joints are designed for load transfer (Gray and Williams, 1989; Kapandji, 1982) and can safely transfer enormous compressive loading forces under normal conditions (Snijders et al., 1993a). • The SIJ has little movement in non-weight bearing (average 2.5 degrees rotation) (Brunner et al., 1991; Jacob and Kissling, 1995; Sturesson et al., 1989; Vleeming et al., 1992a; Vleeming et al., 1992b), and even less in weight bearing (average 0.2 degrees rotation) (Sturesson et al., 2000). • Movement of the SIJ cannot be reliably assessed by manual palpation, particularly in weight bearing (Sturesson et al., 2000; van der Wurff et al., 2000a; van der Wurff et al., 2000b). • Due to its anatomical makeup, intra-articular displacements within the SIJ’s are unlikely to occur. No study utilising a valid measurement instrument has identified positional faults of the SIJ – in fact the converse is true (Tullberg et al., 1998). • Distortions of the pelvis observed clinically are likely to occur secondary to changes in pelvic and trunk muscle activity, resulting in directional strain and not positional changes within the SIJ’s themselves (Tullberg et al., 1998). • No study utilising a valid measurement tool has demonstrated that pelvic manipulation alters the position of the pelvic joints (Tullberg et al., 1998) – pain relief from these procedures is likely to result from nociceptive inhibition based on neuro-inhibitory factors and/or altered patterns of motor activity (Pickar, 2002; Wright, 1995). • Asymmetrical laxity of the SIJ’s, as measured with Doppler imaging, has been shown to correlate with moderate to severe levels of symptoms in subjects with peripartum PGP (Damen et al., 2001). Generalised SIJ laxity is not associated with peripartum pelvic pain (Damen et al., 2001). • When clinical signs of reduced force closure have been identified (positive ASLR), the increased movement is identified at the symphysis pubis – not the SIJ’s (Mens et al., 1999). It is likely that the torsional forces occurring at the SIJ’s can cause strain across pain sensitised tissue. • Pain from the SIJ is located primarily over the joint (inferior sulcus) and may refer distally, but not to the low back (Dreyfuss et al., 1996; Fortin et al., 1994a; Fortin et al., 1994b; Maigne et al., 1996; Schwarzer et al., 1995; Slipman et al., 2000; van der Wurff et al., 2006; Young et al., 2003). • SIJP disorders can be diagnosed using clinical examination (Laslett et al., 2005a; Laslett et al., 2005b; Laslett et al., 2003; Petersen et al., 2004; Young et al., 2003). This includes the finding of pain primarily located to the inferior sulcus of the SIJ’s, positive pain provocation tests for the SIJ’s and an absence of painful lumbar spine impairment. • The SIJ has many muscles that act to compress and control it (force closure), thereby enhancing pelvic stability (creating stiffness) allowing for effective load transfer via the pelvis during a variety of functional tasks (Damen et al., 2002; Mens et al., 2006; O'Sullivan et al., 2002a; Pool-Goudzwaard et al., 2004; Richardson et al., 2002; Snijders et al., 1993a; b; Snijders et al., 2006; Snijders et al., 1998; van Wingerden et al., 2004; Vleeming et al., 1995; Vleeming et al., 1990a; Vleeming et al., 1990b). • PGP disorders may be associated with ‘excessive’ as well as ‘insufficient’ motor activation of the lumbopelvic and surrounding musculature (Hungerford et al., 2003; O'Sullivan and Beales, 2007; O'Sullivan et al., 2002a; Pool-Goudzwaard et al., 2005). CLASSIFICATION OF PELVIC GIRDLE PAIN DISORDERS Chronic pain disorders are complex, multifactorial and need to be considered within a biopsychosocial framework. A different cluster of potential physical, pathoanatomical, psychosocial, hormonal and neuro-physiological factors is associated with each disorder (Figure 1). Needless to say the interactions between these factors are very complex. This highlights the need for a flexible classification and management approach for each disorder. Although the SIJ’s and the surrounding ligamentous and myofascial structures are potentially nociceptive structures (Fortin et al., 1994a; Fortin et al., 1994b; Vilensky et al., 2002), from a neurophysiologic perspective it is well known that ongoing pain can be mediated both peripherally and centrally, and the forebrain can greatly modulate this process (Woolf, 2004; Zusman, 2002). It is therefore logical that PGP disorders can potentially be both peripherally or centrally induced/maintained, with a different balance or dominance of peripheral and central factors associated with each disorder (Elvey and O'Sullivan, 2005). Furthermore with PGP there is the potential contributing role of sex hormones. There are a number of possible pathways by which hormones may influence PGP (Figure 2). There is some evidence that sex hormones are active in pain modulation (Aloisi and Bonifazi, 2006). Sex hormones are also known to influence the inflammatory process in inflammatory pain disorders (Schmidt et al., 2006). Furthermore sex hormones may alter collagen synthesis (Kristiansson et al., 1999), thereby effecting the load capacity of the pelvis. There is some evidence to support the role of hormones in PGP disorders, with higher serum levels of progesterone and relaxin in early pregnancy being found in subjects who develop peripartum PGP compared to those who do not (Kristiansson et al., 1999). Via these processes sex hormones have the potential to contribute to PGP in different clinical presentations (Figure 2). Further research is required to clarify how the role of hormones may differ in these various presentations of PGP. The proposed classification model for PGP disorders is based on the potential mechanisms that can drive the PGP. This classification approach is not exhaustive but rather provides a framework to guide the clinician. Based on the mechanism(s) that underlie these disorders and operating within a biopsychosocial framework, the classification model aims to facilitate the diagnosis, classification (Figure 3), and targeted management of these disorders. The clinical examination The clinical examination is critical to the clinical reasoning process that underpins this diagnosis and classification framework. In the interview process all the following need to be considered: • the pain area (localised versus generalised pain can indicate peripheral from central pain drive) • pain pattern (intermittent versus constant, 24 hour pain pattern, sleep disturbances) • pain intensity • pain behaviour (specific movements and postures that provoke and relieve pain) • levels of disability and impairment • specific pain history (specific and surrounding events that may have contributed to the development of symptoms) • family history of PGP • the patients pain coping strategies (active versus passive coping) • the patients pain beliefs • presence of avoidant behaviours due to fear of movement and other psychosocial factors including present and past history of anxiety and depression • pacing patterns • concurrent presence of disorders of continence and/or sexual dysfunction. Review of radiology if present and screening for specific causes PGP may be indicated from this process. This allows for a determination as to the area and nature of the pain. A thorough physical examination is then required to determine the pain source and behaviour in relationship to the patients’ movement behaviour. Physical tests should include: • palpation of the inferior sulcus of the SIJ and surrounding pelvic ligamentous and myo-fascial structures • provocative tests for the SIJ and surrounding ligamentous and myofascial structures (Laslett et al., 2005a; Laslett et al., 2005b; Laslett et al., 2003; Petersen et al., 2004; Young et al., 2003) • the ASLR test in supine and prone as a test of load transfer, with a positive test resulting in normalisation of ASLR with the addition of pelvic compression (Mens et al., 1999; O'Sullivan and Beales, 2007) • careful analysis of the pain provoking and relieving activities and postures (functional impairments) highlighted from the interview to identify the presence of impairments of movement and motor control as well as avoidance behaviours and determine their relationship to the pain disorder. Determining whether altered motor patterns are adaptive/protective (pain is aggravated when motor control patterns are normalised) or mal-adaptive (pain is relieved when motor control deficits are normalised) is essential. • tests for specific muscle function for the pelvic floor, the abdominal wall, the back muscles, iliopsoas, quadratus lumborum, the gluteal muscles and piriformis. In addition the adjacent areas of the lumbar spine (including neural tissue) and hip joints should be thoroughly investigated to rule out involvement of these areas or to assess for coexisting pathology/dysfunction in these regions. Correlating the patients reported pain behaviour, beliefs and levels of impairment with their clinical presentation (observing for avoidance behaviours, catastrophising etc) is important to determine whether cognitive issues such as fear of movement are present and dominant. On synthesis of this material a diagnosis and classification of the PGP disorder can be made. 1. Specific pelvic girdle pain disorders: Pelvic girdle pain disorders associated with specific pathological processes include inflammatory arthritis, sacroiliitis, infections and fractures. These disorders are amenable to specific diagnosis with appropriate blood screening and radiological investigation. They can be associated with altered patterns of motor control behaviour that are ‘adaptive’ and/or protective of the underlying disorder. Treating the signs and symptoms of these disorders by manual therapy and/or specific exercise interventions is generally not appropriate as it does not address the underlying pain mechanism of the disorder. Physiotherapy may be limited to management of the sequelae of the underlying disease/pathological processes especially in disorders such as ankylosing spondylitis. 2. Non-specific pelvic girdle pain disorders: 2.1 Non-specific inflammatory pelvic girdle pain disorders: There appears to be a group of PGP disorders that present as being inflammatory in nature, rather than mechanical. They are characterised by constant, disabling and nonremitting pain, located in the SIJ’s, that is provoked with weight bearing, pelvic compression (such as a SIJ belt) and with SIJ pain provocation tests. These disorders may show areas of increased uptake on bone scan but are not linked to a specific inflammatory disorder diagnosis based on blood screening. They may be relieved with rest, anti-inflammatory medications and local steroid injections to the SIJ, but are resistant to physical interventions. Although the exact underlying mechanism for these PGP disorders is unknown it is possible that hormonal factors play a role, particularly given their common onset in the first trimester of pregnancy or pain modulation with hormonal cycles or changes. Although the role of sex hormones is purely speculative in this group of patients, further research into their effect is warranted. 2.2 Peripherally mediated (mechanically induced) pelvic girdle pain disorders: These disorders are characterised by localised pain that has a defined anatomical location (SIJ and associated connective tissue and myofascial structures +/- symphysis pubis). The pain is intermittent in nature and is provoked and relieved by specific postures and activities related to vertical or directional loading in weight bearing positions. They are not usually associated with spinal movement related pain and/or spinal movement impairment. A specific pain source at the SIJ and its surrounding structures can usually be identified by specific provocative manual tests (Laslett et al., 2005a; Laslett et al., 2005b; Laslett et al., 2003; Petersen et al., 2004; Young et al., 2003). These disorders are usually associated with consistent local motor control changes (inhibition or excitation). These disorders usually have a clear mechanism or time of onset (either repeated strain or direct trauma to the pelvis or peripartum PGP). It is proposed that these disorders may be classified into two clinical subgroups (Figure 4). 2.2.1 Reduced force closure The first group represents disorders where the peripheral pain drive is associated with excessive strain to the sensitised SIJ’s and/or surrounding connective tissue and myofascial structures secondary to ligamentous laxity (Damen et al., 2001), coupled with motor control deficits of muscles that control force closure of the SIJ’s (Hungerford et al., 2003; O'Sullivan and Beales, 2007; O'Sullivan et al., 2002a). These motor control deficits may have originally developed secondary to the pain disorder, but now their presence is mal-adaptive as the resultant ‘reduced forced closure’ leads to impaired load transfer through the pelvis, acting as a mechanism for ongoing strain and peripheral nociceptive drive for the pain disorder. Hormonal influences on collagen synthesis may be an important factor in this group. These disorders are commonly associated with postpartum PGP and present with a positive ASLR test (normalised with pelvic compression) (O'Sullivan et al., 2002a; Stuge et al., 2004a). The motor control deficits that present in these disorders are variable and are linked to a loss of functional patterns of co-contraction of the local force closure muscles of the pelvis (such as the pelvic floor, the transverse abdominal wall, the lumbar multifidus, iliopsoas and the gluteal muscles). This is commonly associated with attempts to stabilise the lumbopelvic region via co-activation of other trunk muscles (quadratus lumborum, thoracic erector spinae, diaphragm, external oblique, rectus abdominis and vertical fibres of internal oblique). Their primary functional impairments are associated with pain in weight bearing postures such as sitting, standing and walking, or loaded activities inducing rotational pelvic strain associated with coupled spine / hip loading activities (ie. cycling and rowing resulting in posterior rotational strain on ilium). These patients commonly assume postures that are associated with inhibition of the local pelvic muscles (pelvic floor, transverse abdominal wall, lumbar multifidus and the gluteal muscles) such as ‘sway’ standing, ‘hanging off one leg’, ‘slump’ sitting or ‘thoracic upright’ sitting (Dankaerts et al., 2006; O'Sullivan et al., 2006; O'Sullivan et al., 2002b; Sapsford et al., 2006) and present with a loss of lumbopelvic control (inability to disassociate pelvic from thoracic movement). These disorders may be relieved with a SIJ belt (Mens et al., 2006; Ostgaard et al., 1994), training optimal alignment of their spinopelvic posture and functional enhancement of local co-contraction strategies across the pelvis with relaxation of the thoraco-pelvic musculature (O'Sullivan and Beales, 2007). These disorders may gain short term relief from mobilisation, muscle energy techniques, soft tissue massage and manipulation of the SIJ’s (clinical observation) although these in isolation tend not to benefit the long term outcome of the disorder. There is evidence that long lever exercise regimes may aggravate these disorders (Mens et al., 2000). These disorders can be further sub-grouped based on their pattern of motor control dysfunction. Different combinations of motor control deficits may be found within the local lumbopelvic muscles such as is observed in low back pain disorders that result in different directional (vertical, rotational) strain patterns within the pelvis (O'Sullivan, 2005b). Management of these disorders focuses on functionally enhancing force closure across the pelvic structures based on the specific motor control deficits present. The aim of the intervention is to provide functional activation of the motor system in order to control pain and restore functional capacity (Figure 4). There is good evidence to support the efficacy of this type of approach in these disorders (O'Sullivan and Beales, 2007; Stuge et al., 2004a; Stuge et al., 2004b). 2.2.2 Excessive force closure The second group is defined by a group of PGP disorders where the peripheral nociceptive drive is based on excessive, abnormal and sustained loading of sensitised pelvic structures (SIJ’s and surrounding connective tissue and or myofascial structures) from the excessive activation of the motor system local to the pelvis (excessive force closure). This patient group presents with localised pain to the SIJ’s and commonly also the surrounding connective tissue and myo-fascial structures (such as the pelvic floor and piriformis muscles) as well as positive pain provocation tests. However this group of patients has a negative ASLR (no feeling of heaviness). Compression (manual or using a SIJ belt), is often provocative, as is local muscle activation (pelvic floor, transverse abdominal wall, back muscles, iliopsoas, gluteal muscles). They commonly hold habitual erect lordotic lumbopelvic postures associated with high levels of co-contraction across various muscles such as the abdominal wall, pelvic floor, local spinal muscles (lumbar multifidus, psoas major) and in some cases the gluteal and piriformis muscles which may become pain sensitised. These motor control responses often become habitual secondary to excessive cognitive muscle training and/or muscle guarding of the lumbopelvic muscles, and are themselves mal-adaptive (provocative). These patients report pain relief from cardiovascular exercise, relaxation, assuming passive spinal postures (which they seldom do), as well as short term relief with stretching, soft tissue massage, manipulation, muscle energy techniques and cessation of stabilisation exercises. These disorders are commonly associated with the patients belief that their pelvis is ‘unstable’ or ‘displaced’ and that more muscle contraction or ‘pelvic re-alignment’ is beneficial. This is commonly reinforced by the treating therapists’ beliefs. These disorders may be induced by intensive ‘stabilisation exercises’, Pilates, ball exercise, and cognitive muscle exercise training of the abdominal wall, lumbar multifidus and pelvic floor. Patients with these disorders are commonly anxious, under high levels of stress, highly active and seldom rest. Management of these disorders focuses on reducing force closure across the pelvic structures (Figure 4). This is carried out with a combination of approaches such as: general as well as targeted relaxation strategies, breathing control, muscle inhibitory techniques, enhancing passive/relaxed spinal postures, pacing strategies, hydrotherapy, cessation of stabilisation exercise training, and a focus on cardiovascular exercise. Anecdotally this approach appears very effective although clinical studies are required to validate this. 2.2.3 Psychosocial influences on peripherally mediated pelvic girdle pain It is known that chronic pain and PGP disorders are commonly associated with not only physical but also psychosocial and cognitive impairments (Bastiaenen et al., 2004; Bastiaenen et al., 2006; Linton, 2000; 2005; Main and Watson, 1999) (Figure 1). Even in the presence of a dominant peripheral nociceptive drive to PGP (such as described above), cognitive and psychosocial factors are invariably linked to these disorders influencing pain amplification and disability levels to varying degrees. This highlights the need for a biopsychosocial (behavioural) approach to understanding and managing chronic PGP disorders even when they are peripherally mediated in nature. Psychosocial factors have the potential to both ‘up’ regulate or ‘down’ regulate pain. For example, a classification of ‘reduced force closure’ may be associated with associated cognitive impairments such as faulty beliefs, elevated anxiety levels and passive coping strategies that amplifies pain via the central nervous system and promotes high levels of disability associated with the pain disorder. In this case the intervention must address the cognitive impairments associated with the disorder within the motor learning intervention such as by promoting accurate beliefs, relaxation techniques and active coping strategies. On the other hand, if the same ‘reduced force closure’ classification is associated with positive beliefs, active coping strategies and limited functional impairments, then the primary focus can be placed more on the physical impairments of the disorder to establish pain control. Similarly a classification of ‘excessive force closure’ may be associated with underlying stress and anxiety. In this case dealing with these cognitive factors with relaxation, breathing strategies, pacing and cardiovascular exercise is a critical adjunct to the motor learning management of these disorders. Where the psychosocial/cognitive components of the disorders are resistant to change, complementary psychological and/or medical intervention may be essential. 2.4 Central nervous system driven pelvic girdle pain disorders: The mechanisms of central nervous system sensitisation and/or glial cell activation and their involvement in the maintenance of chronic pain states are well known (Hansson, 2006; Woolf, 2004), and may persist even once a peripheral nociceptive drive is removed or has resolved. In this way chronic PGP can be potentially mediated largely or entirely via the central nervous system. In these disorders, the pain may have initially presented as a peripherally driven disorder, but once chronic, the pain does not have a presentation consistent with a peripheral pain source. These pain disorders are commonly associated with widespread, severe, and constant pain that is non-mechanical in nature. They lack a specific detectable peripheral nociceptive drive or pathological basis and are commonly associated with widespread allodynia. These disorders are associated with high levels of physical impairment and social impact, and may be associated with widespread and inconsistent motor control disturbances and abnormal pain behaviours that are secondary to the pain state and do not clearly drive the pain disorder. These disorders are often associated with dominant psychosocial factors (somatisation, catastrophising, pathological fear and/or elevated anxiety, depression, as well as significant social factors such as past history of sexual abuse etc). Although these disorders appear to represent a small sub-group of chronic PGP disorders, they are highly disabling and resistant to physical interventions. Management of these disorders must be multidisciplinary involving medical and psychological management as a primary approach. Functional rehabilitation should aim to enhance normal general body function and address abnormal pain behaviours without a focus on pain. Passive treatments and rehabilitation that focuses on specific muscle control strategies may simply act to reinforce abnormal pain behaviours and hyper-vigilance in these patients. 2.5 Genetics and pelvic girdle pain: The role that genetics play with non-specific PGP disorders is largely unknown although its potential must be recognised. Subjects with PGP are more likely to have a mother or sister who also has PGP (Larsen et al., 1999; Mogren and Pohjanen, 2005) which may implicate a genetic link although social influences may also mediate this effect. A genetic predisposition in PGP patients related to changes in action of relaxin is a proposed as one mechanism of genetic influence on PGP (MacLennan and MacLennan, 1997). Clearly further research into genetic influences is required. 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Correlation of clinical examination characteristics with three sources of chronic low back pain. The Spine Journal 2003;3(6):460-465. Zusman M. Forebrain-mediated sensitization of central pain pathways: 'non-specific' pain and a new image for MT. Manual Therapy 2002;7(2):80-88. CAPTIONS TO ILLUSTRATIONS: FIGURE 1: Factors that need consideration within a biopsychosocial framework for the diagnosis and classification of chronic pelvic girdle pain disorders. FIGURE 1: Genetic factors - potentially influencing all other domains Patho-anatomical factors - structural pathology - ligamentous laxity - identification of peripheral pain generator (sacroiliac joint / pubic symphysis, myofascial / connective tissue) Social factors - relationships – family, friends, work - caring for children - work issues - medical advice and treatment - support structures - compensation – emotional, financial - cultural factors - socio-economic factors - stress Psychological factors - personality type - beliefs & attitudes towards pain disorder - coping strategies – passive vs active - hyper-vigilance - pacing - fear avoidance behaviour - emotions - fear / anxiety / depression / anger / helplessness - illness behaviour Pelvic Girdle Pain Neuro-physiological factors - peripheral sensitisation - hormonal factors - central sensitisation - sympathetic nervous system activity - somatic complaints - glial cell activation Physical factors - mechanism of injury if present - disorder history (pregnancy related) - disorder stage – acute, sub-acute, chronic - area of pain – local / generalised / referred - pain behaviour – intermittent vs constant – provocative and relieving factors - mechanical vs non-mechanical provocation - +ve active straight leg raise - SIJ provocation tests - adaptive vs mal-adaptive movement behaviours - motor control impairments (↑ or ↓ motor activation) - disability levels - activity levels / conditioning / strength / muscle endurance - work / home environment / lifestyle - ergonomic factors FIGURE 2: Possible actions of hormones in the development and maintenance of pelvic girdle pain. Factor affecting hormone levels are also presented. FIGURE 2: Medications Altered Collagen Synthesis Physical Stressors Altered Load Tolerance of Pelvic Ligamentous Structures Direct Modulation of Inflammatory Mediators Toxins Inflammatory Pain Pregnancy Age HORMONE LEVELS Central and/or Peripheral Sensitisation Direct Modulation of Neural Excitability Psychological Stressors Menstrual Cycle Genetics Developmental Organisation of Central Nervous System Structural Basis Behavioural Basis Synthesis Psychosocial Mechanisms FIGURE 3: Mechanism based classification and management of chronic pelvic girdle pain disorders. FIGURE 3: CHRONIC PELVIC GIRDLE PAIN DISORDERS Specific pelvic pain disorders - Specific inflammatory pain disorders (sacroiliitis) - Infections - Fractures Non-specific inflammatory pain disorder Non-specific pelvic pain disorders Centrally mediated pelvic girdle pain Non-dominant psycho-social factors Dominant psycho-social factors Peripherally mediated pelvic girdle pain (+/- cognitive / psychosocial factors resulting in central pain amplification) Reduced force closure Excessive force closure - Medical management - Management advice - Medical management - Functional rehabilitation - Multi-disciplinary management Psychological (cognitive behavioural therapy), medical, functional rehabilitation - Motor learning within cognitive framework (enhance force closure) - Functional restoration - Motor learning within cognitive framework (reduce force closure / relaxation) - Functional restoration FIGURE 4: Sub-classification of pelvic girdle pain disorders with a primary peripheral nociceptive drive. Peripheral drive is perpetuated by mal-adaptive motor control dysfunctions. FIGURE 4: Mal-adaptive chronic pelvic girdle pain disorders where motor control impairments represent dominant underlying driving mechanism for pain Tissue injury / localised pain Motor response Excessive force closure classification - hyper-activity of pelvic muscles with excessive joint compression Factors that may influence pain and motor response pathoanatomical ligamentous laxity physical motor control neurophysiological hormonal psychosocial coping strategies beliefs fear avoidance compensation genetic Resolution of the disorder Non resolution mal-adaptive patterns adopted poor coping strategies prolonged neuromuscular response excessive ↔ reduced spinal stability abnormal tissue loading Management - education – regarding pain mechanism - identify factors that drive motor system - cognitive behavioural approach - relaxation of motor system - relaxation strategies - graded movement restoration - functional restoration - normalise movement behaviour Reduced force closure classification - motor control deficit of pelvic stabilising muscles with loss of force closure Management - education – regarding pain mechanism - cognitive behavioural motor control intervention - pain control (avoid provocation) - specific motor activation - retrain faulty postures and movements - normalise movement behaviour - functional restoration ARTICLE IN PRESS Manual Therapy ] (]]]]) ]]]–]]] www.elsevier.com/locate/math The inter-examiner reliability of a classification method for non-specific chronic low back pain patients with motor control impairment W. Dankaertsa,b,, P.B. O’Sullivana, L.M. Strakera, A.F. Burnetta, J.S. Skouenc,d a School of Physiotherapy, Curtin University, Bentley 6102, WA, Australia Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium c The Outpatient Spine Clinic, Haukeland University Hospital, Bergen, Norway d Section of Physiotherapy Science, Department of Public Health and Primary Health Care, Faculty of Medicine, University of Bergen, Norway b Received 15 June 2004; received in revised form 23 December 2004; accepted 16 February 2005 Abstract The importance of classifying chronic low back pain (LBP) patients into homogeneous sub-groups has recently been emphasized. This paper reports on two studies examining clinicians ability to agree independently on patients’ chronic LBP classification, using a novel classification system (CS) proposed by O’Sullivan. In the first study, a sub-group of 35 patients with non-specific chronic LBP were independently classified by two ‘expert’ clinicians. Almost perfect agreement (kappa-coefficient 0.96; %-of-agreement 97%) was demonstrated. In the second study, 13 clinicians from Australia and Norway were given 25 cases (patients’ subjective information and videotaped functional tests) to classify. Kappa-coefficients (mean 0.61, range 0.47–0.80) and %-of-agreement (mean 70%, range 60–84%) indicated substantial reliability. Increased familiarity with the CS improved reliability. These studies demonstrate the reliability of this multi-dimensional mechanism-based CS and provide essential evidence in a multi-step validation process. A fully validated CS will have significant research and clinical application. r 2005 Elsevier Ltd. All rights reserved. Keywords: Agreement; Classification; Chronic low back pain; Motor control impairment; Reliability 1. Introduction Low back pain (LBP) is one of the most common and costly musculo-skeletal pain syndromes, affecting up to 80% of people at some point during their lifetime (Katz, 2002; van Tulder et al., 2002; Ehrlich, 2003; Woolf and Pfleger, 2003). The re-occurrence rate for LBP is high and these disorders often develop into a chronic fluctuating problem with intermittent flares (Croft et al., 1998; Burton et al., 2004). It has been stated that Corresponding author. School of Physiotherapy Building 408, Curtin University of Technology, GPO Box U1987, Perth, WA 6845, Australia. Tel.: +61 08 9266 3667; fax: +61 08 9266 3699. E-mail address: [email protected] (W. Dankaerts). 1356-689X/$ - see front matter r 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2005.02.001 caring for chronic LBP (CLBP), is one of the most difficult and unrewarding problems in clinical medicine (Leclere et al., 1990) as no approach to diagnosis or treatment has been shown to be clearly definitive or effective. One explanation offered for the inability to identify effective treatments is the lack of success in defining subgroups of patients who are most likely to respond to a specific treatment approach (Leboeuf-Yde et al., 1997; Bouter et al., 1998). Indeed, it has been proposed that the ‘LBP-group’ conceals a large heterogeneous group of patients (McKenzie, 1981; Delitto et al., 1995; Spitzer et al., 1995; Borkan et al., 1998; Bouter et al., 1998; O’Sullivan, 2000; Leboeuf-Yde & Manniche, 2001). Any specific treatment applied to a falsely assumed homogenous sample may result in either failure to respond or ARTICLE IN PRESS 2 W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] aggravation of the disorder (Binkley et al., 1993; Fritz et al., 2000; Leboeuf-Yde & Manniche, 2001; Fritz et al., 2003). The perceived need to accurately classify LBP into homogenous sub-groups to facilitate treatment to be tailored for specific disorders, led to an international forum on LBP ranking the accurate and reproducible characterization of sub-groups of patients with LBP as the top research priority (Borkan et al., 1998). In general, criteria to classify can be defined as belonging to specific theoretical constructs or dimensions of the domain being classified (Bailey 1994; Ford et al., 2003). The shift from thinking about LBP as a patho-anatomical disorder, to viewing LBP as a multifactorial bio-psycho-social disorder is now well accepted (Borkan et al., 2002). As a consequence of this, the different dimensions relevant to classifying the domain of LBP are patho-antomical, signs and symptoms, psychological and social (Waddell, 1987; Ford et al., 2003). For LBP, several classification systems (CSs) from a multitude of perspectives have been proposed. Recent systematic reviews highlight that the multidimensional nature of LBP is not reflected in most CS (Ford et al., 2003; McCarthy et al., 2004). The authors propose that for non-specific CLBP, there is a special need for a mechanism-based CS acknowledging the bio-psycho-social dimensions of this disorder (Woolf et al., 1998; Ford et al., 2003; O’Sullivan, 2004a). When the mechanism or cause of a disorder is known, as long as it is amenable for treatment, treatment of the cause is usually considered more effective than treating its individual signs and symptoms (Zimny, 2004). Table 1 gives an overview of the more commonly used categories and dimensions used to classify LBP patients and their limitations. It is increasingly clear that unidimensional CS’s have limited clinical utility as do not adequately reflect the nature of LBP nor lead to its effective management. For CLBP there is no validated mechanism-based multi-dimensional CS. The development and testing of new CSs based on a multidimensional construct has been recommended (Riddle, 1998; Borkan et al., 2002; O’Sullivan, 2004a). Recently, O’Sullivan (2000, 2004b) proposed a novel CS based on multiple dimensions for a sub-group of patients with NS-CLBP and clinical signs of motor control impairment (MCI). There is indeed considerable evidence documenting the presence of MCI in subjects with NS-CLBP, although, the nature of the impairment is highly variable (Hodges & Richardson, 1997; O’Sullivan et al., 1997; Hodges and Richardson, 1998; O’Sullivan et al., 1998; Hodges and Richardson, 1999; O’Sullivan, 2000; Sahrmann, 2001) and many mechanisms have been postulated for how pain may alter motor planning (Biedermann et al., 1991; Luoto et al., 1999; Hodges, 2001). O’Sullivan’s (2000, 2004b) CS has been described in detail elsewhere but in brief it proposes (based on very strict inclusion and exclusion criteria) that a sub-group of patients with NS-CLBP exists (Table 2). These patients have impairments in the control of their lumbar spine that expose them to repeated stress and strain, thereby providing a basis for ongoing pain. Five distinct clinical patterns were proposed (Appendix A) based on a specific direction of MCI and the hypothesized mechanism underlying the pain disorder (O’Sullivan 2000, 2004b). Whilst O’Sullivan’s CS appears conceptually coherent, its reliability and validity should be established before its widespread use in clinical practice and research. The validation of a CS is a multi-step process (Woolf et al., 1998; Ford et al., 2003; Fritz et al., 2003; Dankaerts et al., 2004; O’Sullivan, 2004a) within which establishing the inter-examiner reliability is a crucial step. Therefore, the aim of the studies reported in this paper was to determine the inter-examiner reliability of this clinical method of classification for NS-CLBP patients with signs of MCI. The first study aimed to determine the level of agreement between ‘expert’ clinicians. The second study aimed to determine the level of agreement between clinicians from Australia and Norway against the ‘expert’ clinicians and to determine the effect of the level of clinician familiarity with the system on their reliability. 2. Methods Since this paper reports on two studies, the methods are outlined separately. Fig. 1 provides a flow-chart of the overall study design. The studies were conducted from January 2002 till December 2003. Approval to conduct both studies was obtained from the Curtin University of Technology, Human Research Ethics Committee, Perth, Western Australia. 2.1. Study 1 Patients with NS-CLBP were independently assessed by two ‘expert’ clinicians and agreement between their diagnoses determined, based on comprehensive subjective and physical examination. 2.1.1. Patients Patients with a classification of NS-CLBP and MCI seeking physiotherapy treatment were recruited from a private multi-disciplinary orthopaedic clinic in the Perth metropolitan area. After screening and further clinical assessment using strict criteria for inclusion and exclusion (Table 2), 35 patients were selected (17 males and 18 females; mean age 37712.73 years; duration of LBP 5.676.0 years; Revised-Oswestry disability score 37711%; Body Mass Index 23.172.2 kg/m2). All ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] 3 Table 1 Different approaches commonly used to classify low back pain (LBP) patients and their limitations Dimension/category Uni-dimensional classification systems Patho-anatomical Approach Limitation for NS-CLBP population Radiological diagnosis (Bernard and Kirkaldy-Willis, 1987) Majority (up to 85%) is classified ‘non-specific’ as no diagnostic imaging procedure is correlated with LBP (Dillingham, 1995; Deyo and Phillips, 1996; Nachemson, 1999; Pearce, 2000) Abnormal findings in asymptomatic individuals are common (Jensen et al., 1994; Boos and Hodler, 1998; Stadnik et al., 1998; Pfirrmann et al., 1999; Borenstein et al., 2001; Humphreys et al., 2002) No insight into the underlying mechanism responsible for the LBP disorder (may be driven by neurophysiological, bio-mechanical and/or psychosocial factors) Identify nociceptive source based on diagnostic injections (Bernard and KirkaldyWillis, 1987; Bogduk, 1995; Young et al., 2003) Signs and Symptoms ‘Treatment based’ approach, using a cluster of signs and symptoms to classify LBP (Delitto et al., 1995) For acute LBP only, a similar approach for chronic LBP has not yet been reported Uni-dimensional approach based only on signs and symptoms has limitations as the basis of a mechanism-based CS Prognosis Based on the future outcome of the patient (Engel and von Korff MKaton, 1996; Dionne et al., 1997; Krause et al., 1998) Of limited use for selection of treatment or management Poor prognosis might simply arise because an appropriate treatment addressing the underlying mechanism behind the pain disorder has not yet been identified or tested Mechanism-based Hypothesized mechanism behind the disorder is one of disc derangement (McKenzie, 1981) Sahrmann (2001): a classification approach for LBP consisting of five different categories based on signs and symptoms and the premise that ‘impairments’ in the way people move are the underlying factor of the musculo-skeletal pain and dysfunction The validity of this approach for NS-CLBP is limited Quebec Task Force Classification (Spitzer, 1987): based on stage of the disorder (acute, sub-acute or chronic), patho-anatomical diagnosis (specific or non-specific, ‘red’ flags), signs and symptoms (area of pain referral), ‘yellow’ flags and work status (psycho-social) Designed to assist in making clinical decisions (e.g. surgery or conservative treatment), establishing a prognosis, and evaluating the quality of care for patients with LBP Of limited use in physiotherapy assessment or treatment planning (Padfield et al., 2002). Does not consider the underlying mechanism behind NS-LBP disorders (apart from differentiating somatic referred from radicular pain) Multi-dimensional classification systems Stage patho-anatomical signs and symptoms psychosocial patients had the protocol explained to them and provided signed consent prior to entering the study. 2.1.2. Examiners The two examiners were musculo-skeletal physiotherapists. One clinician (PO’S) was the developer of the CS and had 18 years experience with patients with LBP. The other clinician (WD) had 12 years of clinical experience with patients with LBP and extensive training by the developer. No consideration is given to the stage of the disorder, area of pain, specific versus non-specific LBP, or yellow flags Classification model assumes that all LBP disorders lie within this classification, ignoring the several other dimensions of LBP within the biopsychosocial framework 2.1.3. Procedure Prior to conducting this study, 20 patients participating in a different study conducted by the authors were independently examined and a clinical diagnosis determined by the ‘expert’ clinicians. The aim of this pilot study was to refine the specific criteria for assignment to each of the five sub-categories and to further train WD (O’Sullivan, 2000, 2004b) (Appendix A). With the aid of videotapes of subjects’ postures and movements, the clinicians’ diagnoses were compared and discussed, and operational definitions were refined. ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] 4 Table 2 Inclusion and exclusion criteria for NSLBP patients with Motor Control Impairmenta Inclusion criteria A history of chronic (43 months) LBP Pain only located to the lower lumbar spine (L4/5 or L5/S1) with minimal radiation Absence of impaired movement of the symptomatic segment in the painful direction of movement or loading (based on clinical joint motion palpation examination) Associated impairments in the control of the motion segment(s) in the provocative movement direction(s) Clear mechanical basis of disorder: specific postural and functional movements that aggravate and ease symptoms; relief of symptoms when reducing the strain to the symptomatic spinal segment in the provocation direction Exclusion criteria More generalized low back pain (beyond L4-5, L5-S1 region) and/or radiating pain Dominant non-organic features (yellow flags) Impaired movement of the symptomatic segment in the painful direction of movement or loading (based on clinical joint motion palpation examination) Based on medical assessment (by general practitioner and/or specialist, including radiological imaging): specific diagnoses for LBP disorder (disc prolapse with radicular pain, severe scoliosis, spondylo-arthrosis, spondylolisthesis, inflammatory or other specific disorders), previous back surgery, and serious causes of LBP (red flag pathology) a All features within the inclusion criteria had to be present; based on O’Sullivan (2000, 2004b). Following informed consent, patients were allocated to one of two examiners. The order of testing by the two examiners varied but for practical reasons could not be randomized. A full clinical examination was performed by the first examiner to identify patients with NS-CLBP who had a classification of MCI based on strict inclusion and exclusion criteria (Table 1). The comprehensive history of the disorder involved: screening for yellow and red flags, reviewing medical imaging, questioning the patient regarding symptom provocation and relief. The full physical examination consisted of a series of active and functional movement tests, articular tests to determine mobility and level of symptom provocation, neural tissue examination, and tests for spinal motor control (O’Sullivan, 2000, 2004b). Patients were then sub-classified into one of the five patterns as per O’Sullivan (O’Sullivan, 2000, 2004b). Within a maximum of 1 week (most patients were evaluated by the second examiner within 24 h) the second examiner performed a similar full examination and nominated a classification. The two examiners acted entirely independently and were blind to the other’s classification of the disorder. Assessment sheets were placed in sealed opaque envelopes and filed for later analysis. Patients were asked not to provide the second examiner with any information regarding the first examination process. 2.2. Analysis study 1 Kappa-coefficient and %-of-agreement were calculated to determine the level of agreement between the ‘expert’ clinicians (Portney and Watkins, 2000). The Kappa-coefficient is a reliability statistic that corrects for agreement due to chance (Altman, 1991). Data were analysed using SPSS Version 10.0. 2.3. Study 2 2.3.1. Examiners Thirteen clinicians (physiotherapists and medical doctors) of two geographically separate regions (seven from Western Australia and six from Norway) were invited to participate based on familiarity with the CS. Examiners’ characteristics are displayed in Table 3. The examiners were classified into two sub-groups based on their level of specific training and clinical experience with the CS. All examiners were required to sign a consent form. 2.3.2. Procedure Patients who participated in Study 1 were asked to consent to be videotaped and to complete a self-reported pain questionnaire. If consent was obtained, they were videotaped performing a series of postures and functional movements that represented commonly reported aggravating postures and movements of these patients (O’Sullivan, 2000, 2004b). This included usual posture in standing, forward bending and return, backward bending and return, single leg standing, usual sitting posture, slump posture, erect upright posture and sit-to-stand to sit. Thirty patients classified identically by the two ‘expert’ clinicians (Study 1) gave consent to be videotaped. Of these, 25 patients were randomly selected to fill the previously determined numbers (based on statistical advice) for each of the five patterns. For each of these 25 patients, a case report was written and videotapes were edited in a standard manner. Approximately 1 month prior to the testing day each participating examiner received an instruction package consisting of a synopsis of the study methodology and a comprehensive summary of the study procedure. Three weeks prior to the testing day a clinical seminar was held ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] 5 Fig. 1. Flow-chart of study design; MCI ¼ motor control impairment. by the developer of the CS for all the Western Australian examiners. One week prior to the testing day a revision session was held. For logistical reasons the training for the Norwegian examiners was slightly different. All Norwegian examiners had previously undertaken two clinical workshops based on the CS conducted by the developer. The same instruction package was sent to Norway 3 weeks prior to the testing. A 2-day workshop was held prior to testing. The blinded examiners had to initially determine the classification for each patient based on the case reports only. In addition, examiners were given the video presentation and were asked to classify the patient based on the combined information. Each examiner placed their assessment booklet in an opaque envelope, which was then sealed prior to further analysis. 2.4. Analysis study 2 Kappa-coefficient and %-of-agreement (Portney and Watkins, 2000) was calculated to determine the level of agreement between the ‘gold standard’ (as determined ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] 6 Table 3 Characteristics of examiners (Study 2) as per level of familiarity with Classification System (CS) Specific training in CS Age (years) Clinical experience (years) Speciality ‘Moderate’ familiar (n ¼ 8) ‘Very’ familiar (n ¼ 5) Clinical education sessions and/or workshops regarding the CS with the developer of the CS 45 (range: 40–54; SD: 7) 20 (range: 10–29; SD: 7) 1 GP/physical medicine 1 MD/clinical neurologist 3 Musculo-skeletal physiotherapists 2 Physiotherapists Postgraduate training under direct supervision of developer of CS 32 (range: 30–33; SD: 1) 9 (range: 7–11; SD: 2) 4 Musculo-skeletal physiotherapists 1 Sports physiotherapist Table 4 Results of Studies 1 and 2 Study 1 Study 2 ‘Expert’ clinicians (n ¼ 2) All clinicians (n ¼ 13) ‘Moderate familiar’ clinicians (n ¼ 8) ‘Very familiar’ clinicians (n ¼ 5) SE+PE S S+V S S+V S S+V Kappa %-of-agreement 0.96 0.32 0.61 0.28 0.55 0.40 0.71 97% 48% 70% 44% 65% 54% 78% (0.13–0.54) (0.47–0.80) (0.13–0.37) (0.47–0.64) (0.39–0.54) (0.58–0.80) (32%–64%). (60%–84%) (32%–52%) (60%–72%) (48%–64%) (68%–84%) Average Kappa-scores (range) and average %-of-agreement (range) SE+PE ¼ based on a comprehensive subjective and physical examination, S ¼ based on subjective information only (case notes), S+V ¼ based on subjective and video. Guidelines for interpreting the strength of the Kappa statistic: o0: poor; 0.00–0.20: slight; 0.21–0.40: fair; 0.41–0.60: moderate; 0.61–0.80: substantial; 0.81–1.00: almost perfect (based on Altman, 1991). by the ‘expert’ clinicians) and the other examiners. Agreement was also analysed based on the level of familiarity with the CS, based on subjective information only, and based on subjective information plus the videotaped recordings. Descriptive statistics were used for the analysis of correct classification for each pattern. Data were analysed using SPSS Version 10.0. 3. Results 3.1. Study 1 Based on independent patient examinations ‘expert’ clinicians demonstrated almost perfect agreement (Kappa-coefficient 0.96; %-of-agreement 97%) (Table 4). 3.2. Study 2 The agreement between examiners and ‘expert’ clinicians based on subjective information and video was substantial (Table 3). Agreement was reduced when examiners made a classification decision based only on subjective information, and among those examiners who had less familiarization with the CS (Table 3). Fig. 2a–e shows the correct classification (%) by all examiners for each pattern. All five patterns could be reliably identified, with the Flexion Shifting pattern best identified (82%), and the Active Extension pattern least correctly identified (62%). 4. Discussion The objective of Studies 1 and 2 was to assess the inter-examiner reliability of a CS for NS-CLBP with MCI as proposed by O’Sullivan (2000, 2004b). Results of Study 1 revealed that there was almost perfect agreement between ‘expert’ clinicians, in identifying and classifying patients with NS-CLBP into specific subgroups of MCI based on a comprehensive clinical examination (Table 4). Results of Study 2 indicate substantial clinical agreement across all five patterns based on combined subjective case reports and video observation of postures and movements. Good interexaminer reliability is an essential first step for a CS to be valid and to be of use, clinically and in research settings (Delitto et al., 1995). The poor reliability when classification was based only on subjective findings was expected. This finding supports that the CS is highly dependent on the assimilation of both the subjective and physical examination (O’Sullivan, 2000, 2004b). Study 2 also aimed to evaluate the importance of specific training in the CS, relative to the ability to accurately apply the CS. The results of this study ARTICLE IN PRESS 100 80 (a) Classification per pattern (%) Classification per pattern (%) W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] correct Flexion Pattern incorrect n=104 68 60 40 20 9 8 11 4 100 (b) correct incorrect 82 80 Flexion Shifting Pattern n=39 60 40 20 18 0 0 0 0 0 Flexion Active Passive MultiShifting Extension Extension directional 100 (c) 80 Active Extension Pattern n =78 correct incorrect 62 60 40 20 20 5 9 4 Flexion 100 Classification per pattern (%) Flexion Classification per pattern (%) 7 (d) 80 Flexion Active Passive MultiShifting Extension Extension directional Passive Extension correct incorrect Pattern n =39 77 60 40 20 20 0 0 0 3 0 Flexion Active Passive MultiShifting Extension Extension directional Classification per pattern (%) Flexion Flexion 100 (e) 80 Multi-directional Pattern n =65 Flexion Active Passive MultiShifting Extension Extension directional correct incorrect 68 60 40 20 14 12 0 6 0 Flexion Flexion Active Passive MultiShifting Extension Extension directional Fig. 2. (a–e) Classification per different pattern (in %) by all examiners in Study 2; n ¼ total number of that specific pattern included 13 (total number of examiners). (Table 4) show a very clear pattern of improved reliability associated with more specific (postgraduate) training. This finding is consistent with Strender et al. (1997) who state that the amount of formal instruction (i.e. continuing education) and specific clinical experience in examination procedures and classification rules is a necessary prerequisite to improving reliability. There appears to be a special need for a mechanismbased CS for NS-CLBP based on a bio-pyscho-social framework (Woolf et al., 1998; McCarthy et al., 2004; O’Sullivan, 2004a; O’Sullivan, 2004b). It is acknowledged that to validate this novel CS as a mechanismbased CS, a multi-step process is required and cannot be based solely on inter-examiner reliability. For this reason a model for clinical research into classification of NS-CLBP has been proposed by the authors (Dankaerts et al., 2004; O’Sullivan, 2004a). This model consists of different stages, each stage dealing with different criteria. Fig. 3 presents a flow-chart summary of the model. This multi-dimensional mechanism-based CS is not an alternative to existing CSs but can be seen as a new development for a sub-group within the NS-CLBP, integrating different aspects of established CSs. For example, the CS proposed by O’Sullivan fits within the QTFC as it uses several criteria set forward by the QTFC: the patient sample consists of ‘non-specific’, ‘chronic’, ‘LBP patients without radiation below the gluteal folds’, absence of ‘red and dominant yellow flags’ and absence of ‘neurological signs’. The proposed CS by O’Sullivan can be seen as a further sub-classification of Category 1 of the QTFC. Similar to McKenzie’s method (McKenzie, 1981; Donelson, 2001), O’Sullivan’s CS is based on a comprehensive patient assessment. Like Delitto’s (1995) treatment-based CS or McKenzie’s method (McKenzie, 1981), O’Sullivan links a very specific intervention to each of the five patterns. Of particular interest for direct comparison with the proposed multi-dimensional CS is the CS developed by Sahrmann (2001) which appears to be more unidimensional in nature. Both classification models assume MCIs as a possible underlying factor in LBP disorders. But there are some substantial differences in the proposed ways to validate the CS and in the method used to classify the patients. Van Dillen et al. (1998) investigated the reliability (among trained therapists) of the individual tests used in criteria for classification according to Sahrmann (2001). The nature of their study ARTICLE IN PRESS 8 W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] Fig. 3. Flow-chart of proposed new model for validation of mechanism-based classification system (CS) for NS-CLBP with Motor Control Impairment (MCI). Current study shaded. design assessed reliability based on individual physical examination items and did not give any insight into the ability of the clinicians to classify the patients into the proposed categories. This reliability study served as a pilot study for a validation study on the CS proposed by Sahrmann (Van Dillen et al., 2003b). According to Bailey (1994), a principal aim of classification is ordering entities into groups with maximum between group heterogeneity and within group homogeneity. In Van Dillen et al. (2003b), the location of symptoms varied from low back only to all kinds of referred locations. All three different stages of LBP disorder were included, without consideration for patho-anatomical findings nor the presence of non-organic signs. The fact that these inclusion criteria consist of several different QTFC categories might have led to a heterogeneous sample. Rather than relying purely on signs and symptoms (Van Dillen et al., 1998, 2003a, b), the current studies used a process of diagnostics to make a clinical determination as to whether the MCI is the driving mechanism behind the disorder or is simply a secondary effect of another process (O’Sullivan, 2004a, b). This process of diagnostics is described in detail elsewhere (Elvey and O’Sullivan, 2004). In contrast with Van Dillen et al. (1998, 2003b), the authors of the current study place a strong emphasis on the subjective history and pain behaviour. Within the CS it is critical in interpreting how the symptoms (as described by the patient during subjective examination) are influenced by changes in postural alignment and movement. Another purpose of taking and integrating history findings is to determine the presence of dominant non-organic features. Strong evidence exists to suggest that psychosocial factors can be an important component of certain NSLBP disorders (Linton, 2000). Psychological processes (cognition, stress, fear, anxiety and depression) are also known to alter motor behaviour (Hodges and Moseley, 2003) influencing patient’s posture and movement (Hodges and Moseley, 2003). Attempts to ‘normalize’ the movement or MCI in many of these disorders would be inappropriate and ineffective (Elvey and O’Sullivan, 2004; O’Sullivan, 2004a). In Van Dillen et al. (1998, 2003b), no other physical examination was performed to identify other underlying mechanisms of pain response. In contrast, in the current study the patients were firstly ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] identified as having an MCI based on a set of characteristics (Table 2). We found it essential to include ‘joint motion palpation’ in Study 1. Firstly, because it was deemed important to identify whether the observed control impairment was linked to the symptomatic level of the patient. Secondly, to identify if the pain disorder is linked to an impairment of ‘movement’ or ‘control’ (Elvey and O’Sullivan, 2004). According to the present authors, in the case of a painful impairment of movement, a treatment (such as manipulative techniques) aiming to promote movement into the painful range is the treatment of choice (Elvey and O’Sullivan, 2004). 4.1. Limitations and recommendations for further studies A limitation of this study was the fact that only the clinicians in Study 1 had to agree on identifying MCI patients from the larger LBP population. Patients in Study 2 must therefore be seen as a selected group that does not fully represent the general population of NSCLBP patients which may be more difficult to classify. Further studies are required to test the ability of clinicians to identify patients with MCI within this NS-CLBP population. The use of ‘expert’ clinicians’ classification as ‘gold standard’ is another limitation of this study. But in the absence of a true criterion standard for MCI diagnosis, this method was justified and has been used by others (Gracovetsky et al., 1995). Because of practical and logistic issues, it was decided to use videotaped recordings of the patients in Study 2. Videotaping has been previously used during reliability studies on visual analysis of gait (Krebs et al., 1985; Eastlack et al., 1991), scapular dysfunction (Kibler et al., 2002) and spinal movements (Fritz et al., 2000). Videotaping has been recommended as an alternative to a test–retest design for assessing inter-examiner reliability with patients who have LBP (Delitto et al., 1992). Both limitations and advantages of videotaping are recognized by the authors. The lack of an actual clinical examination for Study 2 is a limitation and may account for some of the discrepancy in the results between Studies 1 and 2. The advantages of videotaping include: not having to place undue stress on the patient, potentially altering his or her clinical status, while allowing a greater number of participants from geographically distinct regions. In spite of these limitations, the current results support good to high level-of-agreement across all categories based on the methods used. As mentioned above, a multi-step process is required to validate this novel multi-dimensional CS as a mechanism-based classification model. Based on the new proposed model (Fig. 3), several studies have been undertaken to add laboratory and outcome validity to 9 the CS. A laboratory-based test battery, including EMG and 3D-motion analysis, is currently being employed to further validate the clinical diagnosis, determine motor control differences in pain sub-groups with normative data, and ultimately, provide outcome measures for specific interventions. 5. Conclusions The main aim of these two studies was to investigate the inter-examiner reliability of a CS for NS-CLBP patients with MCI. Substantial to excellent reliability was found depending on the level of familiarity. Further research is required to further validate the proposed CS as a mechanism-based CS. The authors believe that the acceptance and integration of a multidimensional mechanism-based CS for NS-CLBP with MCI could have profound implications leading to the application of specific ‘targeted’ interventions for identified sub-groups, and subsequently enhanced treatment efficacy as suggested by Leboeuf-Yde et al. (1997, 2001). Acknowledgment This study was carried out whilst the first author (WD) was an International Postgraduate Research Scholar in Australia and was supported financially by the Head of School of Physiotherapy Scholarship, Curtin University of Technology Western Australia. The authors would also like to acknowledge all examiners (CP, DB, LP, LG, JW, RY, MK, JS, KH, LL, KO, KF, AT) who participated in this study. Special thanks to the administrative staff at ‘Body Logic’ for their help in co-ordinating the appointments for patients, Dr. Ritu Gupta for her statistical advice and Marina Wise for the linguistic corrections. Appendix A The different sub-groups of MCI Patterns and their clinical presentation are briefly described below. Based on O’Sullivan (2000, 2004b) Flexion pattern Definition: MCI of the lumbar spine with a tendency to flexion strain (loss of segmental lordosis) at the symptomatic segment. Flexion pain disorders are associated with functional loss of motor control into flexion resulting in an excessive abnormal flexion strain. Provocative postures/activities: all flexion-related postures (e.g. slouched sitting) and functional activities ARTICLE IN PRESS 10 W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] (forward bending, cycling) are commonly reported as being painful. Easing postures/activities: extension postures/activities where the lumbar spine is lordosed (e.g. standing, sitting with a lumbar roll, walking). Posture and movement analysis: tendency to present with a loss of lumbar lordosis during sitting and standing postures. The pelvis is often positioned in posterior pelvic tilt. During all functional tasks the same tendency to have a loss of lordosis at the ‘symptomatic level’ is noted. Forward bending movements commonly reveal a tendency of an early ‘loss of lower lumbar lordosis’ (lumbar curve reversal). Similar loss of lordosis is accentuated in other functional tasks like sitto-stand, squatting and gait. This is associated with an increased lordosis in the upper lumbar and lower thoracic spine. Specific posture and movement control tests: inability/ lack of motor control to anterior rotate pelvis and extend lower lumbar spine independent from thorax during above-mentioned aggravating postures/ movements. Flexion/lateral shifting pattern Definition: MCI around the lumbar spine with a tendency to flex and laterally shift at the symptomatic segment. Provocative postures/activities: reaching and rotating in one direction in association with flexion postures and / or movements. Easing postures/activities: relief in extended or lordotic postures, stretching to the opposite side from the shift, shift correction (contra-lateral glide from pelvis). Posture and movement analysis: similar to the flexion pattern there is a loss of lumbar segmental lordosis at the affected level with the key feature here an associated lateral shift at the lower lumbar spine level. Minimal precipitation of their spine might deviate into a lateral shift position. E.g.: the lateral shift is accentuated when standing on the foot ipsi-lateral to the shift. Sagittal spinal movements reveal a tendency to laterally deviate during flexion and this is commonly associated with an arc of pain. Tests like ‘sit to stand’ usually reveal a typical flexion pattern presentation (see above) plus a tendency towards lateral trunk shift during the movement with increased weight bearing on the lower limb on the side of the shift. Specific posture and movement control tests: inability/ lack of motor control to anterior rotate pelvis and extend lower lumbar spine independent from thorax during above-mentioned aggravating postures/movements with an associated lateral deviation Active extension pattern Definition: MCI around the lumbar spine with a tendency to hold the lumbar spine actively into extension. Provocative postures/activities: all extension-related postures (standing, erect sitting) and functional activities (carrying out overhead activities, fast walking, running and swimming) are commonly reported as being painful. Also commonly reported as a provocative activity is forward bending (with the key feature here being the tendency to hold the lumbar spine into segmental hyperextension). Easing postures/activities: flexion postures/activities where the lumbar spine is flexed (e.g. crook lying, slouched sitting). Posture and movement analysis: tendency for the lumbar spine to be actively held into segmental hyper-lordosis at the symptomatic segment during upright sitting and standing postures. During all functional tasks such as sit to stand, squatting and forward bending the same tendency to hyper-lordose at the ‘symptomatic segment’ is noted. Forward bending movements commonly reveal increased hip flexion and a tendency of a late ‘loss of lordosis’ (beyond mid range of flexion) or no lumbar curve reversal. Return to neutral from a forward bended position reveals an early hyper-lordosing of the spine at the symptomatic segment. Specific posture and movement control tests: inability/ lack of motor control to initiate a posterior pelvic during above-mentioned aggravating postures/ movements. Passive extension pattern Definition: MCI around the lumbar spine with a tendency to passively over-extend at the symptomatic segment of the lumbar spine. Provocative postures/activities: similar to the active extension pattern all extension-related postures (standing, erect sitting) and functional activities (carrying out overhead activities, fast walking, running and swimming) are commonly reported as being painful. Easing postures/activities: flexion postures/activities where the lumbar spine is de-lordosed (e.g. crook lying, slouched sitting). Posture and movement analysis: tendency for patients to stand into a sway-back posture (thorax posterior to the pelvis) with a segmental hinging at the symptomatic level. Forward bending is often pain free, but on return to neutral they tend to over-extend at the symptomatic level (hinge into extension) and sway pelvis anterior. ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] Specific posture and movement control tests: inability/ lack of motor control to extend the thoraco-lumbar spine above the symptomatic segment with a tendency to hinge into extension at this segment. Multi-directional pattern Definition: multi-directional MCI around the lumbar spine Provocative postures/activities: multi-directional nature of this pattern often reveals pain all weight bearing postures and functional activities. Easing postures/activities: difficulty to find relieving positions during weight bearing Posture and movement analysis: patient may assume a flexed, extended or laterally shifted spinal posture, and may frequently have to alternate them. Excessive segmental shifting and hinging may be observed in all directions, with associated ‘jerky’ movement patterns and reports of ‘stabbing’ pain on movement in all directions with observable lumbar erector spinae muscle spasm. 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Journal of Orthopaedic & Sports Physical Therapy 2004;34(3):105–9 discussion 110-5. 3B2v8:06a=w ðDec 5 2003Þ:51c XML:ver:5:0:1 Prod:Type:ftp pp:1211ðcol:fig::13Þ YMATH : 723 ED:mohan PAGN:savitha SCAN: ARTICLE IN PRESS 1 3 Manual Therapy ] (]]]]) ]]]–]]] www.elsevier.com/locate/math 5 Case study 7 9 11 The use of a mechanism-based classification system to evaluate and direct management of a patient with non-specific chronic low back pain and motor control impairment—A case report W. Dankaertsa,b,, P.B. O’Sullivana, A.F. Burnetta, L.M. Strakera 13 15 a School of Physiotherapy, Curtin University, Bentley 6102, WA, Australia Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium b 17 F Received 20 September 2005; received in revised form 17 March 2006; accepted 16 May 2006 Abstract 23 ’; ’; ’ r 2006 Elsevier Ltd. All rights reserved. PR 21 O O 19 25 Keywords: ’; ’; ’ D 27 1. Introduction 31 Low back pain (LBP) is one of the most common and costly musculoskeletal pain syndromes, affecting up to 80% of people at some point during their lifetime (Katz, 2002; van Tulder, et al., 2002; Ehrlich, 2003; Woolf and Pfleger, 2003). It is reported that in spite of the large number of pathological conditions that can give rise to LBP, 85% of these are without a detected pathoanatomical/radiological abnormality. This population is classified as having ‘non-specific’ (NS) LBP (Waddell, 1987, 2004; Dillingham, 1995) which often develops into a chronic fluctuating problem with intermittent flares (Croft et al., 1998; Burton et al., 2004). Optimal treatment for patients with NS-CLBP remains largely enigmatic. Randomized controlled Trials (RCTs) have failed to find consistent evidence for improved outcomes (Goldby, 2000; Cairns et al., 2002; Assendelft et al., 2004; Frost et al., 2004). One 43 45 47 49 EC R R 41 O 39 C 37 N 35 U 33 Corresponding author. WD, School of Physiotherapy Bld 408, 51 53 55 explanation offered for the inability to identify effective treatments is the lack of success in defining sub-groups of patients who are most likely to respond to a specific treatment approach (Leboeuf-Yde et al., 1997; Borkan et al., 1998; Bouter et al., 1998). Indeed, it has been proposed that the ‘LBP-group’ conceals a large heterogeneous group of patients (McKenzie, 1981; Spitzer, 1987; Borkan et al., 1998; Bouter et al., 1998; LeboeufYde and Manniche, 2001). Any specific treatment applied to a falsely assumed homogenous sample may result in improvement, failure to respond or aggravation of the disorder (Binkley et al., 1993; Fritz et al., 2000; Leboeuf-Yde and Manniche, 2001; Fritz et al., 2003). The shift from thinking about LBP as a pathoanatomical disorder, to viewing LBP as a multi-factorial bio-psycho-social disorder is now well accepted (Borkan et al., 2002; McCarthy et al., 2004; Waddell, 2004). Consequently, the different dimensions relevant to classifying the domain of LBP include patho-anatomical, signs and symptoms, psychological and social (Waddell, 1987; Ford et al., 2003). For LBP, several classification systems (CSs) from a multitude of perspectives have been proposed. A recent review highlights that the multi-dimensional nature of LBP is not reflected in most CSs (Ford et al., 2003; McCarthy et al., 2004). TE 29 Curtin University of Technology, GPO Box U1987, Perth WA 6845, Australia. Tel.: +61 08 9266 3667; fax: +61 08 9266 3699. E-mail address: [email protected] (W. Dankaerts). 1356-689X/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2006.05.004 57 59 61 63 65 67 69 71 73 75 77 79 81 83 YMATH : 723 ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] 19 21 23 25 27 29 31 33 35 37 39 41 51 53 55 65 67 69 71 73 75 77 79 81 83 85 87 A comprehensive subjective and physical examination was first performed on the patient in order to classify her disorder. This information is summarized in Tables 2 and 3, respectively. 95 Definition Flexion Pain disorder resulting from a loss of motor control of the lumbar segment into flexion (associated loss of segmental lordosis) Pain disorder resulting from a loss of motor control of the lumbar segment in the frontal plane (lateral shift pattern). This pattern is also associated with a loss of control into either flexion or extension Pain disorder resulting from the lumbar segment being ‘actively’ held into extension (increased segmental lordosis) Pain disorder resulting from a loss of motor control of the lumbar segment into extension. This is associated with a tendency to passively over extend (hinging) at the symptomatic segment of the lumbar spine Pain disorder resulting from a multi-directional loss of control of a lumbar spinal segment (combinations of above) Multi-directional 63 93 Pattern of MCI Lateral shift (flexion or extension) Active extension Passive extension 61 2. Subjective and physical examination Table 1 Definition of each pattern of motor control impairment (MCI) based on O’Sullivan (2000, 2004) U 49 59 91 N 45 57 89 C 43 47 F 17 O 15 O 13 groups with recent studies revealing altered spinal repositioning sense (O’Sullivan et al., 2003), different spinal posture, kinematics and muscle activation patterns among sub-groups consistent with the CS (Burnett et al., 2004; Dankaerts et al., 2006b, c; O’Sullivan et al., 2005). Despite this growing evidence, there is a lack of longitudinal studies documenting outcome on these specific sub-groups following a targeted intervention. Synchronized recording of surface electromyography (sEMG) and spinal kinematics have been reported frequently in the literature as objective measurement methods in non-outcome LBP research (McGill et al., 1997; Callaghan et al., 1998; Peach et al., 1998; Callaghan and McGill, 2001; Green et al., 2002). This methodological approach has been shown to be sensitive to quantify parameters of motor control and to subclassify NS CLBP patients with MCI during sitting (Dankaerts et al., 2006b, c). An advantage of this form of measurement is that unlike simple range of motion (ROM), measures of sEMG and spinal kinematics have the capacity to quantify the quality and pattern of movement of the spinal-pelvic region through ROM. The aim of this case report is to investigate the use of O’Sullivan’s CS to evaluate and direct management of a patient with NS-CLBP and MCI. An objective laboratory-based assessment (using sEMG and spinal kinematics) was performed on a LBP patient and a matched pain-free control subject. The aim of the laboratory testing was to evaluate its capacity to lend support to the classification of MCI and to quantify the clinical changes in motor control secondary to a specific motor learning intervention. PR 11 TE 9 EC 7 R 5 R 3 While it is well recognized that altered motor control exists with LBP disorders, the changes in motor control in this population are highly variable (O’Sullivan et al., 1997; Hodges and Moseley, 2003; van Dieen et al., 2003). O’Sullivan reported that in general all disorders involving pain in the lumbar region are associated with movement or control impairment. The mere presence of these impairments does not imply that they represent the underlying basis for the disorder, or that correcting these impairments will result in resolving the disorder (O’Sullivan, 2004, 2005). O’Sullivan’s approach to classification is based on a process of ‘diagnostics’ (Elvey and O’Sullivan, 2004) to make a clinical determination as to whether the patient presents with a classification of motor control impairment (MCI) or whether the MCI is simply a secondary effect of another process. This process of diagnostics places a strong emphasis on the correlation between the subjective history, radiology, pain behaviour, physical examination findings and screens for serious pathology (‘red flags’) and psycho-social factors (‘yellow flags’). According to O’Sullivan motor responses present with LBP can be classified into three distinct broad groups (O’Sullivan, 2005). The first group consists of subjects whose motor response is secondary (and adaptive) to an underlying pathological process. The second group consists of subjects where the motor response is secondary to a dominance of psychological and/or social (non-organic) factors. O’Sullivan (O’Sullivan, 2005) proposed that a third group exists where maladaptive motor responses result in chronic abnormal tissue loading leading to ongoing pain and distress. Five distinct (direction based) patterns of MCI have been previously described in detail (O’Sullivan, 2000, 2004). These sub-groups of MCI consist of the; flexion pattern, active extension pattern, passive extension pattern, lateral shifting pattern and a multi-directional pattern (Table 1). Recently, Dankaerts et al. (2006a) showed that these sub-groups could be reliably identified by trained clinicians (physiotherapists and medical doctors). There is also growing support for the validity of these sub- O 1 D 2 97 99 101 103 105 107 109 111 YMATH : 723 ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] 9 11 13 15 17 19 21 23 F 7 O 5 37-year-old female; married; 2- and 4-year-old child Work: part-time (2/7) nurse; involved minimal lifting Home: household activities; picking up and carrying children History: gradual onset of LBP symptoms; starting during the pregnancy of the first child (-4 years); post first pregnancy pain free for 2 years; early in the second pregnancy (-2 years); progressively deteriorating LBP Pain: LBP only (occasionally left buttock region) Aggravating postures: sitting (4 in couch), lying on a hard matrass; sustained forward bending (e.g. doing dishes); sustained backwards bending (e.g. hanging cloths on the wash-line); standing (carrying children) Aggravating activities: walking (4 walking up hill), bending; lifting; previous treatment: fit-ball (stabilising) exercises, specific mobilising exercises (lying flat moving leg) Easing postures/activities: no symptom relief during weight bearing Pain-intensity (VAS): 4/10 (day intake examination); 4/10 (average pain week) Disability-score [Revised-Oswestry (Hudson-Cook, Tomes-Nicholson et al., 1989)]: 34% Fear avoidance [Tampa Scale of Kinesiophobia(Kori, Miller et al., 1990)]: 34/68 Medical imaging: X-rays and CT-imaging–no abnormalities detected Psycho-social risk factors (‘yellow’ flags): absent Serious pathology (‘red’ flags’): absent Key features Localised LBP No signs of neural tissue involvement No reported impairment of movement Multi-directional pain pattern mechanical in nature Absence of radiological abnormality Absence of dominant non-organic features Absence of any signs suggesting serious underlying pathology O 3 57 Table 2 Subjective examination findings PR 1 25 27 41 43 45 47 D 49 4. Laboratory testing 51 An objective laboratory-based assessment (surface EMG and spinal kinematics) was performed on the patient and a matched control subject. The method of this laboratory testing has been described in detail elsewhere (Dankaerts et al., 2006b, c). This case study reports on the lumbo-sacral kinematics and the sEMG 53 55 activity of superficial Lumbar Multifidus (sLM) and transverse fibres of Internal Oblique (trIO) during forward bending. This test was selected since it is frequently used in the LBP research to investigate the reduction in back muscle activity at full body flexion (McGill and Kippers, 1994; Shirado et al., 1995; Kaigle et al., 1998; Gupta, 2001). TE EC R 39 R 37 O 35 C 33 It is acknowledged that rather than relying on one test, classification of a disorder should be based on information of the history taking examination and a ‘cluster of tests’ in combination with a reasoning process (Elvey and O’Sullivan, 2004). In this way, several key features of the physical examination findings (not one single test) consistent with the history, helped to formulate the hypothesis of a classification of multidirectional pattern of MCI disorder (O’Sullivan, 2004). The critical factors of the classification were that this patient had mechanically induced, localized pain that was multi-directional in nature. She had no impairment in range of spinal motion but presented rather with MCI resulting in repeated end range spinal strain and pain. Normalization of her altered motor control (control of the spinal neutral zone) reduced her pain. N 31 3. Classification based on history and physical examination U 29 3 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 5. Intervention 95 The patient’s management consisted of a motor learning intervention based on a cognitive behavioural model. It was progressed over a 14-week period (total of 8 visits, the first 3 were spaced 1 week apart, with subsequent sessions once every 2–3 weeks) to address the impairments in motor control of this patient in a functionally specific manner. The choice of this treatment approach was based on the diagnosis and classification assigned to this patient. Each session included re-evaluation and review of home exercises. The specific exercises and progression was linked with the examination findings and are described in detail by O’Sullivan (2004). Briefly, this motor learning intervention was divided into stages, based on the model proposed by Fitts and Posner (1995). This approach to exercise training focuses on the quality of control of segmental spinal posture and movement. 97 99 101 103 105 107 109 111 YMATH : 723 ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] 4 9 11 13 15 17 19 21 23 25 ROM (fingers to floor) with associated pain Return from forward bending: initiated from the thoraco-lumbar spine by hyper-extending and associated with a lateral shifting pattern and a painful arc (‘catch of pain’); uses hands to return to neutral Backwards bending: provoked pain with a lateral shifting pattern present; full ROM Side bending (R/L): provoked pain with a lateral shifting pattern present; full ROM Single leg standing: prominent lateral shifting pattern (bilateral) Sitting posture: flexed at the lower lumbar spine; extended at the thoraco-lumbar spine Sit to stand: difficulties of shifting load; tendency to hyper-extend and laterally shift the low back 69 Specific movement tests (O’Sullivan, 2004) Inability to maintain neutral lordosis during trunk flexion and load transfer in sitting and inability to achieve a neutral lordosis in standing Repositioning sense in sitting (O’Sullivan et al., 2003): inability to reposition the lumbar spine within a neutral lordosis; ‘over-shoot’ into either flexion (kyphosis) or extension (lordosis) Specific muscle testing (O’Sullivan, 2004) Inability to activate the lower transverse abdominal wall (transverse fibres of internal oblique and lower transversus abdominis) in side lying without breath holding Screening neurological examination (Hall and Elvey, 1999) Absence of neurological findings (provocation testing, reflexes sensation and manual muscle testing) Passive physiological motion segment testing (Maitland, 1986) Absence of segmental movement restriction; increased segmental motion into both flexion and extension at the two lower lumbar segments 29 Key features Full ROM with aberrant quality of motion Through range painful arc with hesitation and lateral movement at midrange of spinal motion No control of mid-position [‘neutral zone’] (Panjabi, 1992a,b) and rapidly moved from one end range spinal posture to the other Use of the hands to assist the return from forward bending Segmental hinging at end of range into extension Loss of neutral zone control of symptomatic spinal segments during loaded postures and spinal movements Increased passive segmental motion into both flexion and extension at the two lower lumbar segments Absence of neurological findings Absence of a segmental movement impairment Provocation of pain linked to specific impairments of control Absence of dominant psycho-social findings (e.g. catastrophizing) 39 TE EC R 37 R 35 D Passive accessory testing (Maitland, 1986) Posterior/Anterior pressure (PA) at L4/5 and L5/S1 levels highly symptomatic; reproductive of the patient’s symptoms 33 47 49 51 53 55 C N 45 This approach operates within a cognitive behavioural framework where the mechanism of the ongoing pain sensitization is explained to the patient. The patient was educated on the mechanics of the spine, the nature of ongoing tissue sensitization with habitual adoption of end range postures and the importance of the muscle system of the lumbo-sacral region to control spinal motion segments and minimize strain. During this cognitive stage the patient was made aware that the postures and patterns of movements that she had adopted had in fact resulted in maintaining her pain. She was made aware she had no control, or sense of her neutral spine positions, nor an ability to isolate the activation of specific muscles (transverse abdominal U 43 O 41 63 67 27 31 61 65 F 7 Standing: hyper-lordotic thoraco-lumbar posture; reduction in tone in the transverse abdominal wall and gluteal muscles Forward bending: splinting pattern (holding lumbar spine into extension); sudden drop into lumbar flexion (curve reversal) at end range; full O 5 59 Posture and movement analysis O 3 57 Table 3 Physical examination findings PR 1 71 73 75 77 79 81 83 85 87 89 91 93 95 97 wall, superficial fibres of lumbar multifidus/sLM, pelvic floor and gluteal muscles). She was first instructed to control her lumbo-pelvic region through the mid-range independent from the thorax (in supine crook lying). At the same session she was instructed to co-activate the pelvic floor, transverse abdominal wall and sLM (Krause et al., 2000) in side lying. She was also instructed to change her sitting posture to maintain a neutral lordosis and relax the thoracolumbar region with co-contraction of the transverse abdominal (TrA/ trIO) wall. This was then progressed to standing. Once she had the ability to assume a neutral lordosis in weight bearing (sitting and standing) with cocontraction of the transverse abdominal wall this was 99 101 103 105 107 109 111 YMATH : 723 ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] 7 9 11 13 15 17 19 21 57 7.1. Forward bending: range of motion 59 The patient’s lumbar spine ROM into forward bending was 481 at the intake examination and 471 at 6-month follow-up. This confirms the clinically observed absence of any movement impairment into forward bending being related to her LBP. This is consistent with the CS. 61 69 Fig. 1 shows the lumbar curvature (L C) in degrees as measured by the FastrakTM in standing and per quartile as the subject bends forward. Negative values represent a lordotic posture. Fig. 1a represents a matched (age and parity) healthy control subject. A pattern of gradual change of L C (from being extended to being flexed) is observed. PR 25 6. Clinical outcome 41 43 45 47 49 51 53 55 TE EC 75 77 79 81 83 85 87 89 R 95 R 39 73 93 97 O 37 71 91 99 C 35 101 N 33 103 U 31 D 27 29 65 67 23 The patient progressed well during the intervention with a gradual decrease in pain and an increase in functional ability. At 14 weeks (end of intervention) she reported to be pain-free with an ability to perform work and household-related tasks. This was associated with a normalization of her movement patterns and absence of pain, improved spinal proprioception, adoption of neutral zone postures and reduced tissue sensitivity. The Revised-Oswestry Disability Questionnaire (Hudson-Cook et al., 1989) was used to document functional progress and disability. The patient’s Revised-Oswestry score (0–100%) decreased across the study period from 34% (pre-intervention) to 14% post-intervention. In the three months following discharge, the patient experienced no exacerbation of LBP-related symptoms and continued to improve functionally (2% at 6-month follow-up). This status was maintained at 1-year followup (0%). The pain intensity score (average over a week; 0–10) decreased from 4/10 pre-intervention, to 2/10 post-intervention, to 0/10 at 6-month follow-up. This pain free status was maintained at 12-month follow-up. The score for fear avoidance (measured by the Tampa Scale of Kinesophobia) decreased from 34/68 to 17 (the minimum score that can be recorded) at 6-month follow-up and was maintained at 12-month follow-up. These scores reflect an absence of pain, transition in function from moderate disability (o40) to no disability and an absence of fear avoidance following the intervention. 63 7.2. Forward bending: kinematic pattern F 5 7. Laboratory testing outcome O 3 incorporated into static holding tasks and dynamic tasks such as single leg stand, sit–stand, squat and lifting (associative stage). As she was generally de-conditioned, she was encouraged to perform gentle aerobic activities (walking, exercise bike) with low level of co-contraction of her transverse abdominal wall while maintaining optimal postural alignment. At the 10-week point she was trained with loaded exercise (hand weights with squats and sit to stand) to increase her global strength and endurance whilst controlling her spinal mid-position. The final (autonomous) stage was reached when the patient reported that she could carry out functional movement tasks with a low degree of attention (Fitts and Posner, 1995). It should be noted that the patient had to achieve each stage of the program before it was progressed. At the end of the 14-week intervention (8 sessions) she was asked to be aware of her spinal posture, and maintain her fitness level by means of regular cardiovascular exercise (alternating between walking and exercise biking). O 1 5 105 107 Fig. 1a–c. Forward bending kinematics; lumbar curvature in degrees (negative values indicate lordosis) as measured by the FastrakTM per quartile (Q) of full movement (time normalised) for (a) control subject; (b) case subject pre-intervention and (c) case subject at 6-month follow-up. 109 111 YMATH : 723 ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] 6 7 Fig. 1b represents the case study patient preintervention. Lumbar spine hyperextension was maintained as she progressed into the forward bending range with a curve reversal at the end (3rd to 4th quartile). At the 6-month follow-up (Fig. 1c) curve reversal was observed more central in range (2nd to 3rd quartile) and this was similar to the control case data (Fig. 1a). 9 7.3. Forward bending: surface EMG findings 11 13 15 17 19 21 7.3.2. Lower transverse fibres of the internal oblique (trIO) Surface EMG profile of the control subject (Fig. 3a) during forward bending and return from forward bending shows a clear pattern of onset–offset–onset for trIO similar to that observed in the sLM at the end of ROM. In contrast the patient pre-intervention (Fig. 3b) showed no clear onset–offset–onset pattern with a deficit in motor activity. At the six month follow-up an onset–offset–onset pattern (similar to the control subject) was observed (Fig. 3c). 7.3.1. Superficial lumbar multifidus (sLM) Fig. 2a shows the raw sEMG activation of the sLM during forward bending and return from forward bending of the matched control subject. A burst of EMG activity, as the subject starts the movement, is observed followed by a pattern of muscle relaxation at the end of the forward bending phase and the return is then associated with a burst in the sLM. This pattern of onset–offset during forward bending is commonly referred to as the flexion relaxation phenomena (FRP). Watson et al. (1997) indicated that this type of dynamic PR 23 25 D 27 TE 29 31 EC 33 35 R 37 R 39 O 41 49 N 47 U 45 C 43 57 59 61 63 65 F 5 O 3 sEMG activity of the paraspinal muscles can be reliably measured and is useful in differentiating CLBP patients from normal controls. Prior to the intervention, the patient displayed increased muscle activity with no FRP during forward bending (Fig. 2b). At the 6-month follow-up, a more normal sEMG pattern, with an FRP was observed (Fig. 2c). O 1 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 101 103 105 51 107 53 109 55 Fig. 2a–c. Raw surface electromyographic activity of the superficial lumbar multifidus during standing, forward bending and return from forward bending for (a) control subject; (b) case subject pre-intervention and (c) case subject at 6-month follow-up. 111 YMATH : 723 ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] 7 57 3 59 5 61 7 63 9 65 11 67 13 69 15 71 17 73 F 1 O 19 O 21 PR 23 25 D 27 TE 29 31 EC 33 35 Fig. 3a–c. Raw surface electromyographic activity of lower transverse fibres of internal oblique during standing, forward bending and return, for (a) control subject; (b) case subject pre-intervention and (c) case subject at 6-month follow-up. R 39 8. Discussion 47 49 51 53 55 C N 45 The patient described in this case report would be ‘classically’ diagnosed as having NS-CLBP based on the absence of any abnormal radiological findings linked to the clinical presentation (Waddell, 1987, 2004; Dillingham, 1995). Based on the CS (O’Sullivan, 2004) this patient was classified as having a multi-directional pattern of MCI. The use of a CS to guide management of patients with LBP and MCI has been reported previously (Maluf et al., 2000;Van Dillen et al., 2003). There are several main differences with the classification approach suggested by O’Sullivan (and applied on this case subject). Rather than relying only on signs and symptoms (Van Dillen et al., 1998, 2003a,b), the proposed CS is based on a process of ‘diagnostics’ (Elvey and O’Sullivan, 2004) to U 43 O 41 77 79 81 83 85 87 89 91 R 37 75 93 95 make a clinical determination as to whether the patient presented with a classification of MCI rather than the altered motor response being a secondary effect of another process. The patient described in this case report presented with full ROM (no movement impairment) in forward and backward bending supporting the classification of MCI. In research and clinical practice, ROM measurements are routinely used to assess patients with LBP. However, these tests do not quantify control parameters during the movement itself. Although excellent convergent validity (Saur et al., 1996; Perret et al., 2001) has been reported for forward bending ROM measurements (compared to dynamic radiographs), of most clinical importance is the lack of discriminative validity highlighted by the weak to non-existing relationship between lumbar ROM measures and functional ability (Parks et 97 99 101 103 105 107 109 111 YMATH : 723 ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 F O 21 O 19 an FRP in the presence of LBP (Ahern et al., 1990; McGill and Kippers, 1994; Shirado et al., 1995; Kaigle et al., 1998; Gupta, 2001). Ahern et al., 1990 proposed that the absence of FRP seen in LBP patients is associated with guarded movements in response to pain. Although pain might be a possible mechanism for the absence of FRP in this case, it is interesting that the muscle activity near end range did not restrict her movement (she achieved full range spinal flexion). Watson et al. (1997) suggested that the assessment of change in FRP could be used in evaluating treatment interventions. EMG data at 6-month follow-up clearly detected a change in motor control pattern during forward bending with a clear FRP present in the sLM (Fig. 2c), which was also associated with a similar pattern in trIO (Fig. 3c). The sEMG findings from trIO during forward bending and return highlight a lack of co-contraction between trIO and sLM prior to the intervention (Fig. 3b). The CLBP literature contains numerous reports on co-activity and synergistic behaviour of muscle groups during trunk flexion-extension and it is well accepted that the trIO muscle increase intra-abdominal pressure (Cresswell et al., 1992; Cholewicki et al., 1999), and act in co-contraction with trA, pelvic floor muscles and back extensors to stabilize the lumbar spine (Panjabi, 1992a,b). Loss of co-contraction between trunk muscles has been previously reported in LBP populations (Hodges and Richardson, 1996; O’Sullivan et al., 1997; Hodges and Richardson, 1999). The absence of cocontraction in combination with the kinematic data, in this case, lends support to the classification of MCI. From a review of the literature it seems that the exact mechanism affecting trunk muscle recruitment in the presence of LBP is not completely understood with several mechanisms hypothesized in the literature (see Hodges and Moseley, 2003 for review). Farfan (1973), Panjabi (Panjabi, 1992a,b) and Richardson et al. (1999) amongst others, have presented models that suggest that deficits in motor control lead to poor control of joint movement, repeated microtrauma and pain. However, the opposite (pain leads to changes in motor control) may also be true. Recent data (e.g. Hodges et al., 2003) has shown that experimentally induced LBP produced changes in the motor control of the trunk muscles similar to that identified in people with LBP. While this does not exclude the possibility that changes in control of the trunk muscles may lead to pain, it does argue that, at least in some cases, pain may cause the changes in control. Hodges et al. (2003) suggested that it is unlikely that the simple inhibitory pathways can mediate the complex changes in motor control of the trunk muscles. The most likely causes are changes in motor planning via a direct influence of pain on the motor centres, factors associated with the attention demand, stressful PR 17 TE 15 EC 13 R 11 R 9 O 7 C 5 N 3 al., 2003; Zuberbier et al., 2001). Based on clinical observations it is very unlikely that for patients with MCI, the lumbar ROM test into forward bending will have any validity as a sensitive outcome measurement. Its hypothesized that impaired spinal mobility may be reflective of a different sub-group of patients with a classification of movement impairment (O’Sullivan, 2005). A novel aspect of this case report is the addition of laboratory-based support to the clinical examination findings of MCI associated with sagittal spinal movement. Despite having full ROM into forward bending, the case subject presented clinically with symptoms through ROM, suggesting a lack of motor control during this movement. The kinematic quantitative assessment was capable of identifying patterns of MCI. Fig. 1b shows that as the patient progressed into forward bending a substantial lordosis (hyper-extension) was maintained, with the curve reversal at the end range (3rd to 4th quartile). This is consistent with O’Sullivan (O’Sullivan, 2000, 2004) who postulated that patients with a multi-directional pattern of MCI have a lack of ability to control a neutral spine posture during functional movements and have a less gradual transition from one end range position to the other. At the 6month follow-up, laboratory testing showed the curve reversal appearing earlier in the range (2nd to 3rd quartile) (Fig. 1c). This is similar to the control case data shown in Fig. 1a. This is an important finding in the search for quantifiable outcome measurements for this sub-group of CLBP patients. This demonstrates that the kinematic analyses were sensitive in detecting changes in motor control following a specific intervention. Further research is warranted to evaluate these parameters in a larger population. For this case report EMG data were also recorded during the laboratory-based testing. Raw EMG is frequently used for pattern recognition and onset–offset EMG detection (Shirado, et al., 1995; Hodges and Richardson, 1997). Marked reduction in back muscle activity at full body flexion, known as FRP, has been investigated in numerous studies (McGill and Kippers, 1994; Shirado et al., 1995; Kaigle et al., 1998; Gupta, 2001). Most studies support that the phenomenon occurs in healthy subjects before reaching the maximum flexed position. In contrast, patients with CLBP don’t typically demonstrate FRP (e.g. Shirado et al., 1995; Kippers and Parker, 1984). These findings are consistent with the pattern observed in the case subject prior to the intervention period, a lack of reduction in electrical activity in sLM (Fig. 2b) during forward bending and the absence of an onset/offset pattern of EMG activity in trIO (Fig. 3b). Several mechanisms have been suggested in the literature that may be responsible for the absence of U 1 D 8 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 101 103 105 107 109 111 YMATH : 723 ARTICLE IN PRESS W. Dankaerts et al. / Manual Therapy ] (]]]]) ]]]–]]] 11 13 15 17 19 21 23 25 27 9. Conclusion 29 39 41 43 TE EC R 37 R 35 O 33 C 31 This case study illustrates the use of O’Sullivan’s CS to guide physiotherapy intervention for a patient with a classification of multi-directional MCI. The kinematic and EMG data support the classification and demonstrated pre-intervention an impairment in the control of the spine during functional movement tasks. Following a motor learning intervention the altered motor control was normalized and was associated with reductions in pain disability and movement-based fear. Ultimately, further research in the form of RCTs is required, comparing intervention based on the CS to other approaches. This is an essential final step to validate this CS-based approach before its widespread use can be advocated (Dankaerts et al., 2006a). N 45 49 51 53 55 U 10. Uncited references 47 F 9 O 7 O 5 Assendelft WJ, Morton SC, Yu EI, Suttorp MJ, Shekelle PG. Spinal manipulative therapy for low back pain. Cochrane Database Systems Review 2004(1):CD000447. Binkley J, Finch E, Hall J, Black T, Gowland C. Diagnostic classification of patients with low back pain: report on a survey of physical therapy experts. Physical Therapy 1993;73(3):138–50 [discussion 150-5]. Borkan J, Van Tulder M, Reis S, Schoene ML, Croft P, Hermoni D. 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A contemporary approach to manual therapy: Grieve’s modern manual therapy. In: Boyling J, Jull G, editors. Amsterdam: Elsevier; 2004. p. 471–94. Farfan HF. Mechanical disorders of the low back. Lea, Febiger: Philadelphia; 1973. Fitts PM, Posner MI. Motor control: theory and practical application. Baltimore: Williams & Wilkins; 1995. PR 3 and fearful aspects of pain, or due to changes in the sensory system (Hodges et al., 2003). For this case subject it is not known whether pain caused the changes in motor control or whether motor control changes lead to pain, or both. However, we hypothesize that the improvement in pain intensity and disability was primarily due to the improvement in her spine motor control, which in turn reduced the peripheral nociceptive drive of pain. It is also acknowledged that cognitive factors such as enhanced patient awareness, improved coping strategies and increased functional capacity (which are all powerful cognitive factors associated with the intervention), are likely to reduce the central drive of pain. The capacity of this form of intervention to impact on the physical and cognitive aspects of the pain disorder is highlighted by the documented reductions in fear avoidance behaviour at 6- and 12-month follow-up. Due to the limitations associated with a case report, the results do not imply a definite answer to the cause–effect question, nor can the patient’s outcomes be generalized across a larger sample. However, the classification of MCI is strengthened by the laboratory-observed changes indicating more normal spinal kinematics and muscle co-activation patterns at 6-month follow-up. D 1 Cairns et al.; Ford et al.; Goldby et al.; O’Sullivan et al., 2006. 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