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Objectives: Our objectives were to identify what and how data relating to the social determinants of health are collected and reported in equity-relevant studies and map these data to the PROGRESS-Plus framework., Study Design and Setting: We performed a scoping review. We ran two systematic searches of MEDLINE and Embase for equity-relevant studies published during 2021. We included studies in any language without limitations to participant characteristics. Included studies were required to have collected and reported at least two participant variables relevant to evaluating individual-level social determinants of health. We applied the PROGRESS-Plus framework to identify and organize these data., Results: We extracted data from 200 equity-relevant studies, providing 962 items defined by PROGRESS-Plus. A median of 4 (interquartile range = 2) PROGRESS-Plus items were reported in the included studies. 92% of studies reported age; 78% reported sex/gender; 65% reported educational attainment; 49% reported socioeconomic status; 45% reported race; 44% reported social capital; 33% reported occupation; 14% reported place and 9% reported religion., Conclusion: Our synthesis demonstrated that researchers currently collect a limited range of equity-relevant data, but usefully provides a range of examples spanning PROGRESS-Plus to inform the development of improved, standardized practices., Competing Interests: Declaration of competing interest E.L.K. has received speaker fees for lectures on pain and rehabilitation from professional and scientific bodies and reimbursement of travel costs related to presentations at scientific conferences/symposia. G.L.M. has received support from Reality Health, ConnectHealth UK, Institutes of Health California, AIA Australia, Workers’ Compensation Boards and professional sporting organisations in Australia, Europe, South America, and North America. Professional and scientific bodies have reimbursed him for travel costs related to presentation of research on pain and pain education at scientific conferences/symposia. He has received speaker fees for lectures on pain, pain education, and rehabilitation and conference travel support from Sequirus. He receives royalties for books on pain and pain education. P.T. has received consulting fees to provide independent medical consultation and professional services. He is an independent Committee Member for clinical trial Data Safety Monitoring Boards for FDA-approved trials being conducted by UCB Biopharma GmbH & SPRL, Parexel International, and Prahealth Sciences. P.T. is an [unpaid] Chair of the Management Subcommittee of the Executive Committee of a registered non-profit independent medical research organization, OMERACT. OMERACT receives unrestricted educational grants from the American College of Rheumatology, European League of Rheumatology, and several pharmaceutical companies listed in this section, which is used to support fellows and international patient groups and support a major international bi-annual conference which results in many peer-reviewed publications. There are no competing interests for any other author., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Clinical tools assessing tactile acuity in people with persistent pain have limitations. Therefore, a novel and semi-automated tool was developed: The Imprint Tactile Acuity Device (iTAD)., Aim: To describe the iTAD prototype and present the psychometric properties of its tactile acuity assessments: the localisation test, the orientation test and the overall score (mean of both tests)., Method: A test-retest design with fifty healthy participants was used to assess intra-rater reliability (ICC (2.1) ), internal consistency (ICC (2.4) ) and measurement error (SEM) of the three assessments (0-100% accuracy scores each) performed at the neck. Using a known-group comparison design, balanced by age and sex, scores of thirty individuals with persistent neck pain were compared to thirty healthy controls to determine construct validity., Results: The ICC (2,1) and ICC (2,4) were 0.60 and 0.78 for the localisation test, 0.66 and 0.77 for the orientation test, and 0.73 and 0.84 for the overall score. The SEMs were 9.0%, 8.1% and 6.0%, respectively. No fixed or proportional bias, or signs of heteroscedasticity were observed. Overall, no between group differences were observed (p = 0.49). In the male subgroup, however, the overall score was lower for people with neck pain than for healthy participants (mean difference (SE); 7.6% (2.5); p = 0.008)., Discussion: The tactile acuity assessments of the iTAD demonstrate moderate reliability and good internal consistency. Measurement errors appear comparable to currently preferred methods. Clear construct validity was not established, but results may be biased by design issues of the prototype. Taken together, the iTAD shows promise but further fine-tuning is needed., (Copyright © 2020. Published by Elsevier Ltd.)

Background: Implicit motor imagery performance is altered in a variety of chronic pain conditions, but it is not known whether this is the case in shoulder pain., Objectives: The aim of this study was to assess implicit motor imagery performance, using a valid and reliable shoulder left/right judgement task in people with shoulder pain., Design: Cross-sectional observational study., Methods: Participants with (n = 369) and without (n = 747) shoulder pain completed the shoulder left/right judgement task (LRJT). Response times (RT), accuracy were determined. Age, gender, hand dominance, current pain intensity, Shoulder Pain and Disability Index (SPADI) and pain duration recorded. Planned analysis included ANOVAs for current pain, RT and accuracy., Results: Gender and hand dominance distribution were similar between groups (p > 0.5). The shoulder pain participants were older, mean age (SD); 47(14)years, than the control group; 41(14)years, p < 0.01. Participants with shoulder pain were slower, mean RT(SD); 1809(746)ms than the controls; 1701(749)ms; p = 0.02, but no different in accuracy, mean % (SD); 93.2(8.5)% to controls; 94.1(9.4)%; p = 0.13. The differences in RT were resolved when age was entered as a covariate (p = 0.83). Regression of the data from the shoulder pain group only found that current pain was positively related to RT (B = 43.97) and negatively to accuracy (B = -0.70)., Conclusions: Participants with shoulder pain do not demonstrate poorer implicit motor imagery performance than people who are pain-free. However, more intense shoulder pain is associated with poorer implicit motor imagery performance. We recommend further research utilising the LRJT in well-defined clinically homogenous groups, with verified pain severity, functional disability, and chronicity., Competing Interests: Declaration of competing interest In the last 5 years, GLM has received support from: ConnectHealth UK, Seqirus, Kaiser Permanente, Workers’ Compensation Boards in Australia, Europe and North America, AIA Australia, the International Olympic Committee, Port Adelaide Football Club and Arsenal Football Club. Professional and scientific bodies have reimbursed him for travel costs related to presentation of research on pain at scientific conferences/symposia. He has received speaker fees for lectures on pain and rehabilitation. He receives book royalties from NOIgroup publications, Dancing Giraffe Press & OPTP, including a book on graded motor imagery, which is mentioned in this article., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objective: Systematic reviews of analgesics for low back pain generally include published data only. Obtaining data from unpublished trials is potentially important because they may impact effect sizes in meta-analyses. We determined whether including unpublished data from trial registries changes the effect sizes in meta-analyses of analgesics for low back pain., Study Design and Setting: Trial registries were searched for unpublished data that conformed to the inclusion criteria of n = 5 individual source systematic reviews. We reproduced the meta-analyses using data available from the original reviews and then reran the same analyses with the addition of new unpublished data., Results: Sixteen completed, unpublished, trials were eligible for inclusion in four of the source reviews. Data were available for five trials. We updated the analyses for two of the source reviews. The addition of data from two trials reduced the effect size of muscle relaxants, compared with sham, for recent-onset low back pain from -21.71 (95% CI: -28.23 to -15.19) to -2.34 (95% CI: -3.34 to -1.34) on a 0-100 scale for pain intensity. The addition of data from three trials (one enriched design) reduced the effect size of opioid analgesics, compared with sham, for chronic low back pain from -10.10 (95% CI: -12.81 to -7.39) to -9.31 (95% CI: -11.51 to -7.11). The effect reduced in the subgroup of enriched design studies, from -12.40 (95% CI: -16.90 to -7.91) to -11.34 (95% CI: -15.36 to -7.32), and in the subgroup of nonenriched design studies, from -7.27 (95% CI: -9.97 to -4.57) to -7.19 (95% CI: -9.24 to -5.14)., Conclusion: Systematic reviews should include reports of unpublished trials. The result for muscle relaxants conflicts with the conclusion of the published review and recent international guidelines. Adding unpublished data strengthens the evidence that opioid analgesics have small effects on persistent low back pain and more clearly suggests these effects may not be clinically meaningful., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Pain is recognised to have both a sensory dimension (intensity) and an affective dimension (unpleasantness). Pain feels like a single unpleasant bodily experience, but investigations of human pain have long considered these two dimensions of pain to be separable and differentially modifiable. The evidence underpinning this separability and differential modifiability is seldom presented. We aimed to fill this gap by evaluating the current evidence base for whether or not the sensory and affective dimensions of pain can be selectively modulated using cognitive manipulations., Methods: A rigorous systematic search, based on a priori search terms and consultation with field experts, yielded 4270 articles. A detailed screening process was based on the following recommendations: (i) evaluation of effectiveness; (ii) examination of methodological rigour, including each study having an a priori intention to cognitively modulate one of the two dimensions of pain; and (iii) sound theoretical reasoning. These were used to ensure that included studies definitively answered the research question., Results: After in-depth critique of all 12 articles that met the inclusion criteria, we found that there is no compelling evidence that the sensory and affective dimensions of pain can be selectively and intentionally modulated using cognitive manipulations in humans., Conclusions: We offer potential explanations for this discrepancy between assumptions and evidence and contend that this finding highlights several important questions for the field, from both the research and clinical perspectives., (Copyright © 2019 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Objective: This proof-of-concept pilot study aimed to investigate if a visual illusion that altered the size and muscularity of the back could be embodied and alter perception of the back., Methods: The back visual illusions were created using the MIRAGE multisensory illusion system. Participants watched real-time footage of a modified version of their own back from behind. Participants undertook one experimental condition, in which the image portrayed a muscled, fit-looking back (Strong), and two control conditions (Reshaped and Normal) during a lifting task. Embodiment, back perception as well as pain intensity and beliefs about the back during lifting were assessed., Results: Two participants with low back pain were recruited for this study: one with altered body perception and negative back beliefs (Participant A) and one with normal perception and beliefs (Participant B). Participant A embodied the Strong condition and pain and fear were less and both perceived strength and confidence were more than for the Normal or the Reshaped condition. Participant B did not embody the Strong condition and reported similar levels of pain, fear strength and confidence across all three conditions., Discussion: An illusion that makes the back look strong successfully induced embodiment of a visually modified back during a lifting task in a low back pain patient with altered body perception. Both participants tolerated the illusion, there were no adverse effects, and we gained preliminary evidence that the approach may have therapeutic potential., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Disruption of cortically-held working body schema has been associated with a variety of pain conditions. A motor imagery technique - the left right judgement task (LRJT) - has been used as an indirect assessment of the integrity of the working body schema. To date there is no LRJT specifically designed to investigate the body schema of persons with shoulder pain., Objectives: To develop a shoulder specific LRJT and assess its validity and reliability., Design: Cross-sectional repeated measures., Methods: Shoulder images were developed representing the shoulder in a variety of postures of graded complexity/awkwardness and degree of rotation. These images were digitally mirrored to represent both left and right shoulders. Participants viewed the images on a computer and determined whether images were of a left or right shoulder., Results: 1413 participants were recruited worldwide and performed the shoulder LRJT (laterality judgement). Mean response time (SD) for the task was 1738(741) ms. Mean accuracy (SD) was 93.5(9.2)%. Chronbach's Alpha for shoulder image response times was 0.95. Participants were fastest responding to images of simple postures and slowest to images corresponding to the more awkward postures (mean difference 520 ms, 95%CI 469-570 ms). Participants were fastest responding to the least rotated images and slowest responding to inverted images, (mean difference 981 ms, 95%CI 919-1043 ms)., Conclusions: The shoulder specific LRJT proved to be highly reliable. Response times increased with complexity and rotation of images, implying a motor imagery strategy was used to complete the task, validating the task as a measure of shoulder joint implicit motor imagery. Abnormal performance cut-offs for age were reported. This result will enable further research examining the relationship between shoulder pain and body schema., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Introduction: Low back pain is the leading worldwide cause of disability, and results in significant personal hardship. Most available treatments, when tested in high-quality randomised, controlled trials, achieve only modest improvements in pain, at best. Recently, treatments that target central nervous system function have been developed and tested in small studies. Combining treatments that target central nervous system function with traditional treatments directed towards functioning of the back is a promising approach that has yet to be tested in adequately powered, prospectively registered, clinical trials. The RESOLVE trial will be the first high-quality assessment of two treatment programs that combine central nervous system-directed and traditional interventions in order to improve chronic low back pain., Aim: To compare the effectiveness of two treatment programs that combine central nervous system-directed and traditional interventions at reducing pain intensity at 18 weeks post randomisation in a randomised clinical trial of people with chronic low back pain., Design: Two-group, randomised, clinical trial with blinding of participants and assessors., Participants and Setting: Two hundred and seventy-five participants with chronic low back pain that has persisted longer than 3 months and no specific spinal pathology will be recruited from the community and primary care in Sydney, Australia., Interventions: Both of the interventions contain treatments that target central nervous system function combined with treatments directed towards functioning of the back. Adherence to the intervention will be monitored using an individual treatment diary and adverse events recorded through passive capture. Participants are informed prior to providing informed consent that some of the treatments are not active. Blinding is maintained by not disclosing any further information. Complete disclosure of the contents of the intervention has been made with the UNSW HREC (HC15357) and an embargoed project registration has been made on the Open Science Framework to meet the Declaration of Helsinki requirement for transparent reporting of trial methods a priori., Intervention a: Participants randomised to Intervention A will receive a 12-session treatment program delivered as 60-minute sessions, scheduled approximately weekly, over a period of 12 to 18 weeks. All treatment sessions are one-on-one. The program includes a home treatment component of 30minutes, five times per week. The intervention comprises discussion of the participant's low back pain experience, graded sensory training, graded motor imagery training and graded, precision-focused and feedback-enriched, functional movement training. Treatment progression is determined by participant proficiency, with mandatory advancement at set time points with respect to a standard protocol., Intervention B: Participants randomised to Intervention B will receive a 12-session treatment program of the same duration and structure as Intervention A. The intervention comprises discussion of the participant's low back pain experience, transcranial direct current stimulation to the motor and pre-frontal cortices, cranial electrical stimulation, and low-intensity laser therapy and pulsed electromagnetic energy to the area of greatest pain. Treatment is delivered according to published recommendations and progressed with respect to a standard protocol., Measurements: The primary outcome is pain intensity at 18 weeks post randomisation. Secondary outcomes will include disability, depression, pain catastrophising, kinesiophobia, beliefs about back pain, pain self-efficacy, quality of life, healthcare resource use, and treatment credibility. Assessment will occur at baseline and at 18, 26 and 52 weeks after randomisation. Treatment credibility will be assessed at baseline and 2 weeks after randomisation only., Analysis: A statistician blinded to group status will analyse the data by intention-to-treat using linear mixed models with random intercepts. Linear contrasts will be constructed to compare the adjusted mean change (continuous variables) in outcome from baseline to each time point between intervention A and intervention B. This will provide effect estimates and 95% confidence intervals for any difference between the interventions., Significance: Preliminary data suggest that combining treatments that target central nervous system function with traditional interventions is a promising approach to chronic low back pain treatment. In the context of modest effects on pain intensity from most available treatments, this approach may lead to improved clinical outcomes for people with chronic low back pain. The trial will determine which, if either, of two treatment programs that combine central nervous system-directed and traditional interventions is more effective at reducing pain intensity in a chronic low back pain cohort. Central nervous system-directed interventions constitute a completely new treatment paradigm for chronic low back pain management. The results have the potential to be far reaching and change current physiotherapy management of chronic low back pain in Australia and internationally., (Copyright © 2016 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.)

Objective: Professional appearance is easily modifiable, and might alter the effects of a clinical encounter. We aimed to determine whether professional attire influences a patient's perception of treatment credibility., Methods: We performed a single-blind randomized controlled study on 128 patients with acute non-specific low back pain who were about to receive treatment in primary care. The treating clinician was randomly allocated to wear formal attire (experimental condition) or casual attire (control condition) to the consultation. Clinicians provided a standardized briefing on the rationale behind the patient's forthcoming treatment. Treatment credibility (Credibility and Expectancy Questionnaire) was assessed immediately after this briefing., Results: All patients received the experimental or control condition as allocated and provided complete primary outcome data. Formal attire had no effect on perceived treatment credibility (Mean difference between groups 1.2 [95%CI-1.1 to 3.5]). Age was the only significant predictor of treatment credibility; older patients rated treatment credibility higher (Beta=0.16 [95%CI 0.08 to 0.24])., Conclusion: In a trial setting, whether or not a clinician is formally dressed has no effect on perceptions of treatment credibility in patients with acute low back pain., Practice Implication: Clinicians should dress comfortably without fear of losing credibility., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

In recent years, there has been increasing interest in studying causal mechanisms in the development and treatment of back pain. The aim of this article is to provide an overview of our current understanding of causal mechanisms in the field. In the first section, we introduce key concepts and terminology. In the second section, we provide a brief synopsis of systematic reviews of mechanism studies relevant to the clinical course and treatment of back pain. In the third section, we reflect on the findings of our review to explain how understanding causal mechanisms can inform clinical practice and the implementation of best practice. In the final sections, we introduce contemporary methodological advances, highlight the key assumptions of these methods, and discuss future directions to advance the quality of mechanism-related studies in the back pain field., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Models of Care (MoCs) for injured workers in the compensation environment recommend adoption of biopsychosocial management approaches. Still, widespread dominance of biomedical constructs at the system, organisational and individual levels of the compensation system prevails, contributing to suboptimal management practices and outcomes for injured workers. Efforts to implement contemporary MoCs in the compensation environment show some promise in improving outcomes. Areas of promise at the organisational level, particularly in the workplace, and at the system level are discussed. Implementation of a contemporary understanding of pain biology as part of the biopsychosocial approach in the management of the person with pain and associated disability has been effective in the non-compensable environment. The implications of this for the compensable environment are explored. Resultant helpful and unhelpful perspectives and behaviours are presented as a blueprint for areas of potential change in development and implementation of MoCs in a compensable environment., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Anecdotally, clinical presentations in which pain seems to be elicited by non-noxious stimuli are often explained using a classical conditioning framework. We were primarily interested in whether (a) clinicians think that pain can be a classically conditioned response to a non-noxious stimulus, and (b) clinicians think that there is evidence to support that idea., Method: Practising healthcare clinicians participated anonymously in an online survey. The information collected included descriptive demographics, clinical experience, personal experience of chronic pain, beliefs about pain, and beliefs about classical conditioning and pain. Responses to the pre-requisite question - whether pain can occur without nociception - were compared to a historical data set from 2004., Results: 1090 people from 57 countries and eight distinct types of health profession completed the survey. 86% stated that pain can occur without nociception; 96% of those believed that pain can be a classically conditioned response to a non-noxious stimulus; 98% of those believed that there is evidence to support that statement. The 2004 data showed that 44% of participants distinguished between pain and nociception., Conclusions: This broad sample overwhelmingly endorsed the ideas that clinicians think that pain can be a classically conditioned response to a non-noxious stimulus and think that there is evidence to support that idea, revealing a discrepancy between beliefs in the clinical community and the scientific evidence. The distinction between nociception and pain has become more accepted by the clinical community over the last 10 years., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Introduction: Pain education is a complex intervention developed to help clinicians manage low back pain. Although complex interventions are usually evaluated by their effects on outcomes, such as pain or disability, most do not directly target these outcomes; instead, they target intermediate factors that are presumed to be associated with the outcomes. The mechanisms underlying treatment effects, or the effect of an intervention on an intermediate factor and its subsequent effect on outcome, are rarely investigated in clinical trials. This leaves a gap in the evidence for understanding how treatments exert their effects on outcomes. Mediation analysis provides a method for identifying and quantifying the mechanisms that underlie interventions., Aim: To determine whether the effect of pain education on pain and disability is mediated by changes in self-efficacy, catastrophisation and back pain beliefs., Design: Causal mediation analysis of the PREVENT randomised controlled trial., Participants and Setting: Two hundred and two participants with acute low back pain from primary care clinics in the Sydney metropolitan area., Intervention: Participants will be randomised to receive either 'pain education' (intervention group) or 'sham education' (control group)., Measurements: All outcome measures (including patient characteristics), primary outcome measures (pain and disability), and putative mediating variables (self-efficacy, catastrophisation and back pain beliefs) will be measured prior to randomisation. Putative mediators and primary outcome measures will be measured 1 week after the intervention, and primary outcome measures will be measured 3 months after the onset of low back pain., Analysis: Causal mediation analysis under the potential outcomes framework will be used to test single and multiple mediator models. A sensitivity analysis will be conducted to evaluate the robustness of the estimated mediation effects on the influence of violating sequential ignorability--a critical assumption for causal inference., Discussion and Significance: Mediation analysis of clinical trials can estimate how much the total effect of the treatment on the outcome is carried through an indirect path. Using mediation analysis to understand these mechanisms can generate evidence that can be used to tailor treatments and optimise treatment effects. In this study, the causal mediation effects of a pain education intervention for acute non-specific low back pain will be estimated. This knowledge is critical for further development and refinement of interventions for conditions such as low back pain., (Copyright © 2015 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.)

A growing body of literature associates musculoskeletal disorders with cortical reorganisation. One condition in which reorganisation is established and treatments that 'train the brain' are being widely used is chronic back pain. Recent evidence suggests that treatments that involve tactile training are more effective if they incorporate multisensory mechanisms, most obviously vision. With regard to back pain however, we must first determine if tactile function is enhanced by incorporating other modalities. A series of three cross-over experiments were conducted in healthy pain-free subjects to determine whether tactile acuity is enhanced when participants can see the skin of their back during testing. An initial randomised cross-over experiment suggested tactile acuity was significantly enhanced when participants could see their backs (t(25) = -4.226, p < 0.001, r = 0.65). However, a second replication experiment was not corroborative. Both the second (F(3,66) = 1.00, p = 0.398) and third (t(9) = 0.969, p = 0.358) experiments suggested that seeing the back did not significantly affect tactile acuity, confirming that our initial results were likely due to chance. The principle that visual feedback improves tactile acuity at the hand does not apply to the back. These results strongly suggest that attempts to enhance tactile training by incorporating vision will not offer the benefit to treatment of back pain that has been observed for treatment of hand pain., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

A growing body of literature suggests that alterations in brain structure and function are a feature of chronic back pain. Tactile acuity is considered a clinical signature of primary somatosensory representation and offers a simple measure of cortical reorganisation. Clinical interpretation of test scores from an individual patient is hampered by variance in published normative values and less than ideal inter-rater reliability. These problems might be mitigated in people with unilateral back pain by using the patient as their own control and comparing tactile acuity at the painful site to performance at the corresponding position on the non-painful side. The first step in exploring this approach is to quantify the normal side-to-side difference in healthy populations. We pooled data from three previous studies that measured lumbar tactile acuity bilaterally in healthy controls using similar protocols. We calculated the mean and variance of the absolute error between sides, the standard error of measurement and the reliable change index (RCI). The mean difference between sides was 3.2 mm (±5.2) when assessed vertically and 1.9 mm (±3.2) when assessed horizontally. The standard error of measurement was 4.2 mm when assessed vertically and 2.7 mm when assessed horizontally. The RCI suggests that differences of greater than 13 mm when assessed horizontally and 17 mm when assessed vertically equate to 95% confidence that a difference truly exists. Several assumptions related to the application of this approach need to be investigated further., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Understanding motor imagery of the hands and feet has led to promising new treatments for neurological and chronic pain disorders. We aimed to extend this line of research to the neck with a view to developing the definitive platform study upon which clinical and experimental studies can be based. In a cross-sectional experiment with a convenience sample, volunteers were shown 40 photographs of a model with their head turned to the left or right. Images were presented in random order and orientation. Participants judged the direction of neck rotation. They also completed a left/right hand judgment task. 1361 pain-free participants volunteered. Mean ± standard deviation response time (RT) for making left/right judgments of neck rotation was 1.621 ± 0.501 s. Median accuracy was 92.5%. RT was related to age, gender, and handedness (p < 0.001). That is, RT increased with age, was greater in females than in males and was greater in left-handers than in right-handers. Accuracy reduced with age (p < 0.001), but was unaffected by gender or handedness. Judgments were more accurate when images showed a neck rotated to the right than when they showed a neck rotated to the left (p < 0.001). The magnitude of image rotation affected both response time and accuracy (p < 0.001). In general, the performance parameters established for left/right limb judgments also apply for left/right neck rotation judgments. The current work establishes the definitive normative values against which clinical and experimental groups can be compared and reveals unpredicted effects of the direction neck rotation and the orientation of the image., (Copyright © 2013. Published by Elsevier Ltd.)

Objective: Chronic pain is a common problem that is associated with mood disorders such as depression. The Depression, Anxiety, and Stress Scales (DASS-21) questionnaire is commonly used to help measure disordered mood. In this study, we used Rasch analysis to analyze the clinimetric properties of the DASS-21 in a chronic low back pain sample., Study Design and Setting: A Rasch analysis was conducted on data collected as a part of a randomized hospital-based placebo-controlled trial. DASS-21 questionnaires were completed by the 154 enrolled participants., Results: The DASS-21 subscales fit the Rasch model. No differential item functioning was detected for age, gender, pain severity, or disability. Reliability for individual use was supported for the depression subscale (Person Separation Index [PSI]=0.86) but group use only for the anxiety (PSI=0.74) and stress (PSI=0.82) subscales. A DASS-21 aggregate score of "negative affect" lacked fit to the Rasch model (χ(2)=191.48, P<0.001)., Conclusion: This is the first study that used Rasch analysis to demonstrate that the DASS-21 subscales demonstrate adequate measurement properties for research involving groups with chronic pain. Only the DASS-21 depression subscale demonstrated adequate reliability for use with individuals with chronic pain. The use of a single DASS-21 aggregate score as a measure of "negative affect" was not supported., (Copyright © 2012 Elsevier Inc. All rights reserved.)

There is increasing evidence that chronic pain problems are characterised by alterations in brain structure and function. Chronic back pain is no exception. There is a growing sentiment, with accompanying theory, that these brain changes contribute to chronic back pain, although empirical support is lacking. This paper reviews the structural and functional changes of the brain that have been observed in people with chronic back pain. We cast light on the clinical implications of these changes and the possibilities for new treatments but we also advise caution against concluding their efficacy in the absence of solid evidence to this effect., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

There is a lack of quantitative evidence for spinal postures that are advocated as 'ideal' in clinical ergonomics for sitting. This study quantified surface spinal curves and examined whether subjects could imitate clinically 'ideal' directions of spinal curve at thoraco-lumbar and lumbar regions: (i) flat - at both regions (ii) long lordosis - lordotic at both regions (iii) short lordosis - thoracic kyphosis and lumbar lordosis. Ten healthy male subjects had 3-D motion sensors adhered to the skin so that sagittal spinal curves were represented by angles at thoracic (lines between T1-T5 and T5-T10), thoraco-lumbar (T5-T10 and T10-L3) and lumbar regions (T10-L3 and L3-S2). Subjects attempted to imitate pictures of spinal curves for the flat, long lordosis, short lordosis and a slumped posture, and were then given feedback/manual facilitation to achieve the postures. Repeated measures analysis of variance was used to compare spinal angles between posture and facilitation conditions. Results show that although subjects imitated postures with the same curve direction at thoraco-lumbar and lumbar regions (slumped, flat or long lordosis), they required feedback/manual facilitation to differentiate the regional curves for the short lordosis posture. Further study is needed to determine whether the clinically proposed 'ideal' postures provide clinical advantages.

Studies of lumbar intradiscal pressure (IDP) in standing and upright sitting have mostly reported higher pressures in sitting. It was assumed clinically that flexion of the lumbar spine in sitting relative to standing, caused higher IDP, disc degeneration or rupture, and low back pain. IDP indicates axial compressive load upon a non-degenerate disc, but provides little or no indication of shear, axial rotation or bending. This review is presented in two main parts. First, in vivo IDP data in standing and upright sitting for non-degenerate discs are comprehensively reviewed. As methodology, results and interpretations varied between IDP studies, in vivo studies measuring spinal shrinkage and spinal internal-fixator loads to infer axial compressive load to the discs are also reviewed. When data are considered together, it is clear that IDP is often similar in standing and sitting. Secondly, clinical assumptions related to IDP in sitting are considered in light of basic and epidemiologic studies. Current studies indicate that IDP in sitting is unlikely to pose a threat to non-degenerate discs, and sitting is no worse than standing for disc degeneration or low back pain incidence. If sitting is a greater threat for development of low back pain than standing, the mechanism is unlikely to be raised IDP.

The contribution of the trunk muscles to spinal stability is well established. There is convincing evidence for the role of multifidus in spinal stability. Recently, emphasis has shifted to the deep fibres of this muscle (DM) and five key clinical beliefs have arisen: (i) that DM stabilizes the lumbar spine whereas the superficial fibres of lumbar multifidus (SM) and the erector spinae (ES) extend and/or rotate the lumbar spine, (ii) that DM has a greater percentage of type I (slow twitch) muscle fibres than SM and ES, (iii) that DM is tonically active during movements of the trunk and gait, whereas SM and ES are phasically active, (iv) that DM and the transversus abdominis (TrA) co-contract during function, and (v) that changes in the lumbar paraspinal muscles associated with LBP affect DM more than SM or ES. This paper reviews the biomechanical, electromyographic, histochemical and morphological data that underpin these beliefs. Although there is support for the importance of the lumbar multifidus and the specific contribution of this muscle to intervertebral control, several of the clinical beliefs have little or no support and require further evaluation. These findings have implications for clinical practice.

Low back pain (LBP) and neck pain are associated with dysfunction of the trunk and neck muscles, respectively, and may involve common or similar mechanisms. In both cases, dysfunction may compromise spinal control. Anecdotally, neck pain patients commonly develop LBP. This study investigated the possibility that trunk muscle function is compromised in neck pain patients and that compromised trunk muscle function is associated with increased risk of LBP. Fifty-four neck pain patients and 52 controls were assessed on an abdominal drawing-in task (ADIT) and on self-report tests. Performance on the ADIT was able to detect neck pain patients with 85% sensitivity and 73% specificity. Catastrophizing and McGill pain questionnaire (affective) scores were higher in patients with an abnormal task response than in patients with an uncertain or normal response, although the self-report data did not predict task performance. Fifty subjects from each group were contactable by telephone at 2 years. They were asked whether they had experienced persistent or recurrent LBP since the assessment. Subjects (patients and controls) who obtained an abnormal response on the ADIT were 3 to 6 times more likely to develop persistent or recurrent LBP than those who obtained an uncertain or normal response. ADIT performance was the main predictor of development of LBP in patients. The results suggest that reduced voluntary trunk muscle control in neck pain patients is associated with an increased risk of developing LBP.

This paper presents an approach to rehabilitation of pain patients. The fundamental principles of the approach are (i) pain is an output of the brain that is produced whenever the brain concludes that body tissue is in danger and action is required, and (ii) pain is a multisystem output that is produced when an individual-specific cortical pain neuromatrix is activated. When pain becomes chronic, the efficacy of the pain neuromatrix is strengthened via nociceptive and non-nociceptive mechanisms, which means that less input, both nociceptive and non-nociceptive, is required to produce pain. The clinical approach focuses on decreasing all inputs that imply that body tissue is in danger and then on activating components of the pain neuromatrix without activating its output. Rehabilitation progresses to increase exposure to threatening input across sensory and non-sensory domains.

Many authors report changes in the control of the trunk muscles in people with low back pain (LBP). Although there is considerable disagreement regarding the nature of these changes, we have consistently found differential effects on the deep intrinsic and superficial muscles of the lumbopelvic region. Two issues require consideration; first, the potential mechanisms for these changes in control, and secondly, the effect or outcome of changes in control for lumbopelvic function. Recent data indicate that experimentally induced pain may replicate some of the changes 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. There are many possible mechanisms, including changes in excitability in the motor pathway, changes in the sensory system, and factors associated with the attention demanding, stressful and fearful aspects of pain. A new hypothesis is presented regarding the outcome from differential effects of pain on the elements of the motor system. Taken together these data argue for strategies of prevention and rehabilitation of LBP.