Validity and Diagnosis in Physical and Rehabilitation Medicine: Critical View and Future Perspectives.

ABSTRACT: Obtaining a diagnosis is an essential and integral part of physical and rehabilitation medicine in practice and research. Standardized psychometric properties are required of any classifications, diagnostic criteria, and diagnostic rules used. Physicians and researchers, in physical and rehabilitation medicine, need to understand these properties to determine the accuracy and consistency of their diagnosis. Although chronic musculoskeletal pain disorders are among the highly prevalent disorders seen in physical and rehabilitation medicine, limitations regarding existing diagnostic criteria for chronic musculoskeletal pain disorders still exist. Hence, the quest for developing diagnostic tools for chronic musculoskeletal pain that align with the standard properties remains open. These are discussed with an example for existing diagnostic criteria for fibromyalgia. This article primarily aimed to provide an overview of standard psychometric properties. A secondary aim was to critically appraise the tools currently used to diagnose chronic musculoskeletal pain disorders. The challenges and limitations of existing diagnostic tools are discussed. Potential approaches on how to improve the conceptualization of the construct of musculoskeletal pain disorders are also discussed. Adopting a network perspective, for example, can better constitute the disease instead of a single known underlying etiology for persistent or recurrent pain symptoms.

The Pediatric Pain Screening Tool (PPST) can Rapidly Identify Elevated Pain and Psychosocial Symptomatology in Treatment-Seeking Youth with Acute Musculoskeletal Pain.

This cross-sectional study examines the utility of the Pediatric Pain Screening Tool (PPST) for rapidly assessing pain and psychosocial symptomatology in treatment-seeking youth with acute musculoskeletal pain. Participants were 166 youth (10-18 years, 53.6% female) participating in one of two larger cohort studies of youth with acute musculoskeletal pain. Youth completed the PPST and measures of pain, pain-related fear, pain catastrophizing, pain-related disability, and sleep quality. Participants were categorized into PPST risk groups using published cut-offs. ANOVA and chi-square examined associations between PPST risk groups and self-report measures; receiver operating characteristic (ROC) analyses examined associations among PPST scores and clinical reference cut-offs. The PPST classified 28.3% of youth as high, 23.5% as moderate, and 48.2% as low-risk. Females were more likely to be high-risk. ANOVAs revealed differences in clinical factors by PPST risk group particularly differences among youth labeled high versus low-risk. ROC analyses showed the PPST is effective in discriminating "cases" versus "non-cases" on pain-related disability, pain-fear and catastrophizing. Results reveal the PPST is effective for rapidly screening youth with acute pain for pain and psychosocial symptomatology. An important next step will be to examine the validity of the PPST in predicting recovery outcomes of acute pain samples. PERSPECTIVE: This article presents the Pediatric Pain Screening Tool (PPST) as a measure for rapidly screening youth with acute pain for pain and psychosocial symptomatology. The tool categorizes youth into low, moderate or high-risk groups and discriminates among those with versus without clinically significant levels of disability, pain-related fear and catastrophizing.

Evaluation of musculoskeletal discomfort using item response theory: creation of a scale based on the self-reported pain symptoms.

This study aims to build a scale for musculoskeletal discomfort based on the self-reported musculoskeletal pain by individuals. For this, methods such as factorial analysis and item response theory were used. A sample of 1821 workers of a footwear industry participated in this study. The scale consists of four levels ranging from mild to maximum discomfort. In mild discomfort (level 60), pain symptoms are rare or frequent in regions such as cervical and trapezoidal area, low back, shoulders, wrists, ankles and feet. At level 70, rare or frequent symptoms affect regions of the upper and lower limbs. At level 80, frequent symptoms become common in the trunk and in most of the upper and lower limbs. At level 90, the symptoms become daily in elbows, thighs and knees. The scale showed signs of validity and proved useful for studies in ergonomics. Practitioner Summary: Methods such as factor analysis and item response theory were used to build a four-level musculoskeletal discomfort scale that can be useful to complement the screening process for workers with musculoskeletal pain. The scale shows signs of accuracy, in addition to validity and reliability. Abbreviations: WMSD: work-related musculoskeletal disorders; CTT: classic test theory; IRT: item response theory; KMO: Kaiser-Meyer-Olkin; PR: pain rarely; PO: pain often; PE: pain everyday; DIF: differential item functioning.

Psychological Subgrouping to Assess the Risk for the Development or Maintenance of Chronic Musculoskeletal Pain: Is This the Way Forward?

BACKGROUND: Because musculoskeletal pain problems are so prevalent, new methods of evaluating and treating patients are needed to increase effectiveness. Subgrouping is a method wherein patients are classified into defined groups on the basis of psychosocial factors with the expectation of more specific and tailored treatments can be prescribed for them. For those seeking care for a new episode, the risk of developing chronic pain-related disability is assessed, whereas, for those with existing pain, the risk for the maintenance of the chronic pain problem is evaluated. AIM: The purpose of this narrative review is to examine how patients are classified into subgroups with regard to methods of evaluation and to ascertain whether subgrouping actually facilitates treatment. RESULTS: For the development of disability, screening tools, for example, the Örebro Musculoskeletal Pain Screening Questionnaire, accurately stratify patients into groups (eg, high, medium, low risk) that predict future pain-related work disability. In addition, several studies show that treatments that directly key in on risk groups enjoy enhanced outcomes compared with treatment as usual. For the maintenance of chronic musculoskeletal pain problems, there are several instruments that classify patients into specific groups or profiles, for example, on the basis of the avoidance and endurance model or the International Classification of Functioning, Disability and Health (ICF) assessment. Although some evidence shows that these classifications are related to treatment outcome, we found no study that directly tested a system for providing treatment matched to the subgrouping for maintenance. CONCLUSIONS: We conclude that it is possible to reliably subgroup patients with musculoskeletal problems. Likewise, treatments that address the risk factors in the screening procedure may enhance outcomes compared with treatment as usual. More work is needed, however, to better understand the mechanism, so that assessment methods can be improved, and treatment specific to subgroups can be developed and evaluated.

Shoulder pain has most impact on poor quality of life among various types of musculoskeletal pain in middle-aged and elderly people: Yakumo study.

Objectives: To investigate the severity and effect on quality of life (QOL) of various types of pain in healthy volunteers.Methods: A total of 384 subjects (male: 158, female: 226, average age: 63 years) were included in a prospective cohort study (Yakumo study). Shoulder pain, low back pain (LBP), sciatica, knee pain, and the American Shoulder and Elbow Surgeons (ASES) shoulder score were evaluated with SF-36.Results: The prevalence of shoulder pain, LBP, sciatica, and knee pain was 42%, 44%, 16%, and 48%, respectively, with similar severities of pain. Shoulder pain visual analogue scale (VAS) and ASES shoulder scores were significantly correlated with SF-36 domains. Subjects with poor physical QOL had significantly higher VAS scores for all pain types and a lower ASES shoulder score. Shoulder pain VAS was also significantly related to poor mental QOL. Multivariate regression analysis adjusted for age and gender showed that shoulder pain VAS (OR: 1.25, p < .05) and 10-m gait speed (OR: 1.82, p < .05) were significant independent risk factors for poor physical QOL.Conclusion: Only shoulder pain of similar severity to other pain and shoulder complaints impacted on both physical and mental QOL. The severity of shoulder pain was an independent risk factor for poor physical QOL.

A study exploring the prevalence of Extremity Pain of Spinal Source (EXPOSS).

OBJECTIVES: To investigate the proportion of patients that present with isolated extremity pain who have a spinal source of symptoms and evaluate the response to spinal intervention. METHODS: Participants (n = 369) presenting with isolated extremity pain and who believed that their pain was not originating from their spine, were assessed using a Mechanical Diagnosis and Therapy differentiation process. Numerical Pain Rating Scale, Upper Extremity/Lower Extremity Functional Index and the Orebro Questionnaire were collected at the initial visit and at discharge. Global Rating of Change outcomes were collected at discharge. Clinicians provided MDT 'treatment as usual'. A chi-square test examined the overall significance of the comparison within each region. Effect sizes between spinal and extremity source groups were calculated for the outcome scores at discharge. RESULTS: Overall, 43.5% of participants had a spinal source of symptoms. Effect sizes indicated that the spinal source group had improved outcomes at discharge for all outcomes compared to the extremity source group. DISCUSSION: Over 40% of patients with isolated extremity pain, who believed that their pain was not originating from the spine, responded to spinal intervention and thus were classified as having a spinal source of symptoms. These patients did significantly better than those whose extremity pain did not have a spinal source and were managed with local extremity interventions. The results suggest the spine is a common source of extremity pain and adequate screening is warranted to ensure the patients ́ source of symptoms is addressed.

New concepts of pain.

Active research is being conducted on musculoskeletal pain, and recent concepts will help clinicians and researchers to develop better approaches: -the new pain taxonomy recently has been modified with a third descriptor with the concept of nociplastic pain. -the latest International Classification of Diseases (ICD-11) includes an IASP task force that developed a new classification system for pain. In this new classification, one can differentiate primary musculoskeletal pain including fibromyalgia and low back pain and secondary musculoskeletal pain related to specific etiologies. -the concept of central sensitization in inflammatory rheumatic diseases is increasingly discussed. In these conditions, even with very active biological treatment, almost a third of patients are still complaining of persisting pain. These persisting pain states under adequate treatment, without any sign of inflammation, led researchers to look for evidence of central sensitization states.

Gender-related differences in psychometric properties of WHO Disability Assessment Schedule 2.0.

Objective of this study was to investigate the gender-related differential item function of 12-item WHODAS 2.0 amongst patients with chronic musculoskeletal pain. This was a cross-sectional survey study among 1,988 patients at a university Physical and Rehabilitation Medicine outpatient clinic. To assess DIF, WHODAS 2.0 items were dichotomized as `none' rated by respondents as `0' versus `any limitation' rated as `1,2,3 or 4'. The item response theory analysis was used to define discrimination and difficulty parameters of a questionnaire. The probit logistic regression was used to test uniformity of DIF between gender groups. The results of DIF analysis were presented and evaluated graphically as item characteristic curves based on 2-parameter IRT analysis of dichotomized responses. High to perfect discrimination ability was observed for all the items except one. Difficulty levels of eight items were shifted towards the elevated disability level, four items demonstrated a perfect difficulty property. Significant DIF between genders was observed in seven of 12 items. The detected DIFs were uniform. For item `household', `emotional affection' and `work', men had to experience slightly worse disability than women to achieve the same score. A reverse effect was observed for items `concentration', `washing', `dressing' and dealing with strangers. In this study, significant DIF between genders was found in seven of twelve items of 12-item WHODAS 2.0. amongst 1988 patients with chronic musculoskeletal pain. All the detected DIFs were uniform. Regardless gender-related DIF shown in seven out of 12 items, we recommend using and studying 12-item WHODAS 2.0 in different populations.

The IASP classification of chronic pain for ICD-11: chronic secondary musculoskeletal pain.

Chronic musculoskeletal pain is defined as chronic pain arising from musculoskeletal structures such as bones or joints. Although comprising the most prevalent set of chronic pain conditions, it was not represented appropriately in the 10th edition of the International Classification of Diseases (ICD-10), which was organized mainly according to anatomical sites, was strongly focused on musculoskeletal disease or local damage, and did not consider the underlying mechanisms of pain. The new ICD-11 classification introduces the concept of chronic primary and secondary musculoskeletal pain, and integrates the biomedical axis with the psychological and social axes that comprise the complex experience of chronic musculoskeletal pain. Chronic primary musculoskeletal pain is a condition in its own right, not better accounted for by a specific classified disease. Chronic secondary musculoskeletal pain is a symptom that arises from an underlying disease classified elsewhere. Such secondary musculoskeletal pain originates in persistent nociception in musculoskeletal structures from local or systemic etiologies, or it may be related to deep somatic lesions. It can be caused by inflammation, by structural changes, or by biomechanical consequences of diseases of the nervous system. It is intended that this new classification will facilitate access to patient-centered multimodal pain management and promote research through more accurate epidemiological analyses.

Multigroup latent class model of musculoskeletal pain combinations in children/adolescents: identifying high-risk groups by gender and age.

BACKGROUND: To investigate the combinations of Musculoskeletal pain (MSP) (neck, shoulder, upper and low back pain) among a sample of Iranian school children. METHODS: The MSP combinations was modeled by latent class analysis (LCA) to find the clusters of high-risk individuals and multigroup LCA taking into account the gender and age (≤ 13 years and ≥ 14 years of age categories). RESULTS: The lowest and highest prevalence of MSP was 14.2% (shoulder pain in boys aged ≥14 years) and 40.4% (low back pain in boys aged ≤13 years), respectively. The likelihood of synchronized neck and low back pain (9.4-17.7%) was highest, while synchronized shoulder and upper back pain (4.5-9.4%) had the lowest probability. The probability of pain at three and four locations was significantly lower in boys aged ≥14 years than in other gender-age categories. The LCA divided the children into minor, moderate, and major pain classes. The likelihood of shoulder and upper back pain in the major pain class was higher in boys than in girls, while the likelihood of neck pain in the moderate pain class and low back pain in the major pain class were higher in children aged ≥14 years than those aged ≤13 years. Gender-age specific clustering indicated a higher likelihood of experiencing major pain in children aged ≤13 years. CONCLUSIONS: The findings highlight the importance of gender- and age-specific data for a more detailed understanding of the MSP combinations in children and adolescents, and identifying high-risk clusters in this regard.

[Medicolegal Assessment for Chronic Musculoskeletal Pain - 4th Update of the German Guideline for Medicolegal Assessment of Persons in Chronic Pain]. / Begutachtung chronischer muskuloskeletaler Schmerzen.

Medicolegal assessments of claimants with chronic muskuloskeletal pain conditions are frequent. The first German guideline published in 2005 for the medicolegal assessment of claimants in chronic pain is now available in its 4th version (AWMF register number 094 - 003). It gives recommendations for the procedure and serves to ensure the quality of expert opinions when complaints about chronic pain are the leading symptom. In the current version, the indications for ordering medical assessments in pain syndromes have been reformulated, the assessment criteria have been adapted to ICF specifications, and an unequivocal distinction has been introduced between questions of state and causal assessment. A separate chapter on symptom validity assessment has been engrafted.

Multidisciplinary Assessment of 100 Athletes With Groin Pain Using the Doha Agreement: High Prevalence of Adductor-Related Groin Pain in Conjunction With Multiple Causes.

OBJECTIVE: To examine the prevalence of different causes of groin pain in athletes using the recent Doha consensus classification of terminology and definitions of groin pain in athletes. DESIGN: Descriptive epidemiological study. SETTING: Multidisciplinary sports groin pain clinic at Aspetar Orthopedic and Sports Medicine Hospital, Doha, Qatar. PATIENTS: The clinical records of 100 consecutive athletes with complaints of groin pain who attended the multidisciplinary sports groin pain clinic between January and December 2014 were analyzed. MAIN OUTCOME MEASURES: The causes of groin pain were categorized according to terminology and definitions agreed upon at the Doha consensus meeting on groin pain classification in athletes. The classification system has 3 main subheadings; defined clinical entities for groin pain (adductor-related, iliopsoas-related, inguinal-related, and pubic-related groin pain), hip-related groin pain, and other causes of groin pain in athletes. RESULTS: The majority of athletes were male (98%) soccer players (60%). Multiple causes for groin pain were found in 44% of the athletes. Adductor-related groin pain was the most prevalent defined clinical entity (61% of athletes), and pubic-related groin pain was the least prevalent (4% of athletes). CONCLUSIONS: Adductor-related groin pain is the most commonly occurring clinical entity in this athlete population in mainly kicking and change of direction sports and frequently, multiple causes are found. CLINICAL RELEVANCE: This is the first study to use the Doha agreement classification system and highlights the prevalence of adductor-related groin pain and that often multiple clinical entities contribute to an athlete's groin pain. Consequently, prevention programs should be implemented with these factors in mind.

Inter-examiner classification reliability of Mechanical Diagnosis and Therapy for extremity problems - Systematic review.

BACKGROUND: Mechanical Diagnosis and Therapy (MDT) is used in the treatment of extremity problems. Classifying clinical problems is one method of providing effective treatment to a target population. Classification reliability is a key factor to determine the precise clinical problem and to direct an appropriate intervention. OBJECTIVES: To explore inter-examiner reliability of the MDT classification for extremity problems in three reliability designs: 1) vignette reliability using surveys with patient vignettes, 2) concurrent reliability, where multiple assessors decide a classification by observing someone's assessment, 3) successive reliability, where multiple assessors independently assess the same patient at different times. DESIGN: Systematic review with data synthesis in a quantitative format. METHOD: Agreement of MDT subgroups was examined using the Kappa value, with the operational definition of acceptable reliability set at ≥ 0.6. The level of evidence was determined considering the methodological quality of the studies. RESULTS/FINDINGS: Six studies were included and all studies met the criteria for high quality. Kappa values for the vignette reliability design (five studies) were ≥ 0.7. There was data from two cohorts in one study for the concurrent reliability design and the Kappa values ranged from 0.45 to 1.0. Kappa values for the successive reliability design (data from three cohorts in one study) were < 0.6. CONCLUSION: The current review found strong evidence of acceptable inter-examiner reliability of MDT classification for extremity problems in the vignette reliability design, limited evidence of acceptable reliability in the concurrent reliability design and unacceptable reliability in the successive reliability design.

The Role of Language Use in Reports of Musculoskeletal Pain Among Hispanic and Non-Hispanic White Adolescents.

OBJECTIVE: This study examined the role of English language use in the reported frequency of musculoskeletal pain among Hispanic and non-Hispanic White youth. METHOD: This is a secondary data analysis using a cross-sectional sample of 12,189 Hispanic and non-Hispanic White adolescents recruited for the National Longitudinal Study of Adolescent to Adult Health. Respondents were classified into three groups: (a) English-speaking non-Hispanic Whites, (b) English-speaking Hispanics, and (c) Spanish-speaking Hispanics. RESULTS: After controlling for body mass index and demographic, socioeconomic, and behavioral variables, Spanish-speaking Hispanics reported the least frequent musculoskeletal pain ( OR = 0.415, 95% CI [0.361, 0.477]; p < .001), followed by English-speaking Hispanics ( OR = 0.773, 95% CI [0.690, 0.865]; p < .001). CONCLUSION: The experience of musculoskeletal pain is a physiological as well as a cultural phenomenon. IMPLICATIONS FOR PRACTICE: Health care providers should consider the role of language use in reports of pain in Hispanic and non-Hispanic White adolescents.

Validity and responsiveness of the French version of the Örebro Musculoskeletal Pain Screening Questionnaire in chronic low back pain.

PURPOSE: The assessment of a broad range of biopsychosocial aspects is important in the rehabilitation of patients with chronic low back pain (CLBP) for the prediction of outcome as well as for evaluation. The objective of this study was to test the responsiveness, construct validity and predictive value of the Örebro Musculoskeletal Pain Screening Questionnaire (OMPSQ) compared to other instruments widely used to assess biopsychosocial aspects in patients with CLBP. METHODS: 111 patients with CLBP admitted to an inpatient rehabilitation completed a set of questionnaires on biopsychosocial aspects at baseline and at discharge. Ninety-eight patients responded at three months for an assessment of the return to work status. Responsiveness of the OMPSQ, the ability to detect change in the construct of interest, was investigated by a set of hypotheses on correlations with widely used questionnaires. We tested the hypothesis that the changes in the OMPSQ would vary along with the responses in the Patient's Global Impression of Change. Prediction of disability at discharge, work status at three months and time to return to work was evaluated with linear, logistic and cox regression models. RESULTS: The OMPSQ showed good predictive values for disability and return to work and construct validity of the instrument was corroborated. Seventy-nine percent of our hypotheses for responsiveness could be confirmed, with the OMPSQ showing the second highest change during the rehabilitation. CONCLUSIONS: The OMPSQ can also be applied in patients with CLBP, but for the assessment of change in psychosocial variables one should add specific questionnaires.

Classification of patients with low back-related leg pain: a systematic review.

BACKGROUND: The identification of clinically relevant subgroups of low back pain (LBP) is considered the number one LBP research priority in primary care. One subgroup of LBP patients are those with back related leg pain. Leg pain frequently accompanies LBP and is associated with increased levels of disability and higher health costs than simple low back pain. Distinguishing between different types of low back-related leg pain (LBLP) is important for clinical management and research applications, but there is currently no clear agreement on how to define and identify LBLP due to nerve root involvement. The aim of this systematic review was to identify, describe and appraise papers that classify or subgroup populations with LBLP, and summarise how leg pain due to nerve root involvement is described and diagnosed in the various systems. METHODS: The search strategy involved nine electronic databases including Medline and Embase, reference lists of eligible studies and relevant reviews. Selected papers were appraised independently by two reviewers using a standardised scoring tool. RESULTS: Of 13,358 initial potential eligible citations, 50 relevant papers were identified that reported on 22 classification systems. Papers were grouped according to purpose and criteria of the classification systems. Five themes emerged: (i) clinical features (ii) pathoanatomy (iii) treatment-based approach (iv) screening tools and prediction rules and (v) pain mechanisms. Three of the twenty two systems focused specifically on LBLP populations. Systems that scored highest following quality appraisal were ones where authors generally included statistical methods to develop their classifications, and supporting work had been published on the systems' validity, reliability and generalisability. There was lack of consistency in how LBLP due to nerve root involvement was described and diagnosed within the systems. CONCLUSION: Numerous classification systems exist that include patients with leg pain, a minority of them focus specifically on distinguishing between different presentations of leg pain. Further work is needed to identify clinically meaningful subgroups of LBLP patients, ideally based on large primary care cohort populations and using recommended methods for classification system development.

Muscleskeletal pain in dysphonic women.

OBJECTIVE: To investigate the location, frequency and intensity of muscle pain in dysphonic functional/organofunctional women in comparison to women with healthy voices. METHODS: Sixty women, ranging in age from 18 to 45 years, divided into two groups: Dysphonic Group (DG) - 30 women with functional or organofunctional dysphonia; Non-Dysphonic Group (NDG) - 30 women without vocal complaints, and with adapted voices. All answered a protocol, marking the localization, frequency and intensity symptoms of pain on the temporal area, masseters, submandibular areas, larynx/pharynx, front and back of the neck, shoulders, upper back, lower back, elbows, fists/hands/fingers, hip/this, knees and ankles/feet. The volunteer should report the frequency in which pain was present in the last 12 months: no, rarely, frequently or always. The intensity of pain was measured by visual-analogue scales. The DG and NDG groups were compared using the Mann-Whitney test (p<0.05). RESULTS: The women of the DG reported significantly greater frequency of submandibular area (p=0.008), laryngeal pain (p<0.001), front of the neck (p=0.015), back of the neck (p=0.001), shoulder pain (p=0.027), upper back (p=0.027) and also reported significant greater intensity of pain in the larynx/pharynx (p=0.022) and back of the neck (p=0.003). CONCLUSION: The frequency and intensity of musculoskeletal pain was more frequent and more intense in dysphonic women than in women without vocal complaints, showing that pain may be related to functional and organofunctional dysphonia in women.

Effects of Feldenkrais method on chronic neck/scapular pain in people with visual impairment: a randomized controlled trial with one-year follow-up.

OBJECTIVE: To determine whether the Feldenkrais method is an effective intervention for chronic neck/scapular pain in patients with visual impairment. DESIGN: Randomized controlled trial with an untreated control group. SETTING: Low vision center. PARTICIPANTS: Patients (N=61) with visual impairment (mean, 53.3 y) and nonspecific chronic (mean, 23.8 y) neck/scapular pain. INTERVENTIONS: Participants were randomly assigned to the Feldenkrais method group (n=30) or untreated control group (n=31). Patients in the treatment group underwent one 2-hour Feldenkrais method session per week for 12 consecutive weeks. MAIN OUTCOME MEASURES: Blind assessment of perceived pain (visual analog scale [VAS]) during physical therapist palpation of the left and right occipital, upper trapezius, and levator scapulae muscle areas; self-assessed degree of pain on the Visual, Musculoskeletal, and Balance Complaints questionnaire; and the Medical Outcomes Study 36-Item Short-Form Health Survey bodily pain scale. RESULTS: Patients undergoing Feldenkrais method reported significantly less pain than the controls according to the VAS and Visual, Musculoskeletal, and Balance Complaints questionnaire ratings at posttreatment follow-up and 1-year follow-up. There were no significant differences regarding the Medical Outcomes Study 36-Item Short-Form Health Survey bodily pain scale ratings. CONCLUSIONS: Feldenkrais method is an effective intervention for chronic neck/scapular pain in patients with visual impairment.

Spinal cord injury pain.

Chronic pain associated with traumatic spinal cord injury (SCI) can be quite challenging to the physiatrist. This highly prevalent condition within the SCI population requires an appropriate evaluative approach including a thorough history, a targeted physical examination, and appropriate use of diagnostic testing. The International Spinal Cord Injury Pain Classification allows for a reasonable categorization of the various pain syndromes and may assist in selecting a reasoned treatment strategy. A multitude of management approaches exist including nonpharmacologic, pharmacologic, and interventional approaches. This article provides an overview of the epidemiology, classification, evaluation, and management of SCI-associated pain.

Low back related leg pain: an investigation of construct validity of a new classification system.

BACKGROUND: Leg pain is associated with back pain in 25-65% of all cases and classified as somatic referred pain or radicular pain. However, distinction between the two may be difficult as different pathomechanisms may cause similar patterns of pain. Therefore a pathomechanism based classification system was proposed, with four distinct hierarchical and mutually exclusive categories: Neuropathic Sensitization (NS) comprising major features of neuropathic pain with sensory sensitization; Denervation (D) arising from significant axonal compromise; Peripheral Nerve Sensitization (PNS) with marked nerve trunk mechanosensitivity; and Musculoskeletal (M) with pain referred from musculoskeletal structures. OBJECTIVE: To investigate construct validity of the classification system. METHODS: Construct validity was investigated by determining the relationship of nerve functioning with subgroups of patients and asymptomatic controls. Thus somatosensory profiles of subgroups of patients with low back related leg pain (LBRLP) and healthy controls were determined by a comprehensive quantitative sensory test (QST) protocol. It was hypothesized that subgroups of patients and healthy controls would show differences in QST profiles relating to underlying pathomechanisms. RESULTS: 77 subjects with LBRLP were recruited and classified in one of the four groups. Additionally, 18 age and gender matched asymptomatic controls were measured. QST revealed signs of pain hypersensitivity in group NS and sensory deficits in group D whereas Groups PNS and M showed no significant differences when compared to the asymptomatic group. CONCLUSIONS: These findings support construct validity for two of the categories of the new classification system, however further research is warranted to achieve construct validation of the classification system as a whole.