Search

Classification of musculoskeletal pain based on underlying pain mechanisms (nociceptive, neuropathic, and nociplastic pain) is challenging. In the absence of a gold standard, verification of features that could aid in discrimination between these mechanisms in clinical practice and research depends on expert consensus. This Delphi expert consensus study aimed to: (1) identify features and assessment findings that are unique to a pain mechanism category or shared between no more than 2 categories and (2) develop a ranked list of candidate features that could potentially discriminate between pain mechanisms. A group of international experts were recruited based on their expertise in the field of pain. The Delphi process involved 2 rounds: round 1 assessed expert opinion on features that are unique to a pain mechanism category or shared between 2 (based on a 40% agreement threshold); and round 2 reviewed features that failed to reach consensus, evaluated additional features, and considered wording changes. Forty-nine international experts representing a wide range of disciplines participated. Consensus was reached for 196 of 292 features presented to the panel (clinical examination-134 features, quantitative sensory testing-34, imaging and diagnostic testing-14, and pain-type questionnaires-14). From the 196 features, consensus was reached for 76 features as unique to nociceptive (17), neuropathic (37), or nociplastic (22) pain mechanisms and 120 features as shared between pairs of pain mechanism categories (78 for neuropathic and nociplastic pain). This consensus study generated a list of potential candidate features that are likely to aid in discrimination between types of musculoskeletal pain.

Background: Musculoskeletal (MSK) injury is one of the major causes of persistent pain. Objective: This systematic literature review explored the factors that lead to persistent pain following a MSK injury in the general population, including athletes. Methods: A primary literature search of five electronic databases was performed to identify cohort, prospective, and longitudinal trials. Studies of adults who diagnosed with a MSK injury, such as sprains, strains or trauma, were included. Results: Eighteen studies involving 5372 participants were included in this review. Participants’ ages ranged from 18–95 years. Most of the included studies were of prospective longitudinal design. Participants had a variety of MSK injuries (traumatic and non-traumatic) causing persistent pain. Multiple factors were identified as influencing the development of persistent pain following a MSK injury, including high pain intensity at baseline, post-traumatic stress syndrome, presence of medical comorbidities, and fear of movement. Scarcity of existing literature and the heterogeneity of the studies made meta-analysis not possible. Conclusions: This systematic review highlighted factors that might help predict persistent pain and disability following MSK injury in the general population, including athletes. Identification of these factors may help clinicians and other health care providers prevent the development of persistent pain following a MSK injury.

Background The prevention and rehabilitation of multisite musculoskeletal pain would benefit from studies aiming to understand its underlying mechanism. Autonomic imbalance is a suggested mechanism for multisite pain, but hardly been studied during normal daily living. Therefore, the aim of the study is to investigate the association between multisite musculoskeletal pain and cardiac autonomic modulation during work, leisure and sleep. Methods This study is based on data from the “Danish Physical activity cohort with objective measurements” among 568 blue-collar workers. Pain intensity scales were dichotomized according to the median of each scale, and the number of pain sites was calculated. No site was regarded as the pain-free, one site was considered as single-site musculoskeletal pain and pain in two or more sites was regarded as multisite musculoskeletal pain. Heart rate variability (HRV) was measured by an electrocardiogram system (ActiHeart) and physical activity using accelerometers (Actigraph). Crude and adjusted linear mixed models were applied to investigate the association between groups and cardiac autonomic regulation during work, leisure and sleep. Results There was no significant difference between groups and no significant interaction between groups and domains in the crude or adjusted models for any HRV index. Significant differences between domains were found in the crude and adjusted model for all indices, except SDNN; sleep time showed higher values than leisure and work time, except for LF and LF/HF, which were higher during work. Conclusion This cross-sectional study showed that multisite musculoskeletal pain is not associated with imbalanced cardiac autonomic regulation during work, leisure and sleep time. Electronic supplementary material The online version of this article (10.1186/s12891-018-2312-3) contains supplementary material, which is available to authorized users.

Background and aims Musculoskeletal pain may negatively affect work ability, especially when work demands are high and/or physical capacity of the worker is low. This study investigated the association between intensity of musculoskeletal pain in multiple body regions and work ability among young and old workers with sedentary and physical demanding jobs. Methods Currently employed wage earners (n=10,427) replied to questions about pain intensity, work ability, and physical work demands. The odds ratio (OR) for having a lower level of work ability in relation to the physical demands at work were modeled using logistic regression controlled for various confounders. Results The OR for lower work ability increased with higher pain intensity in all regions among workers with sedentary and physical work. The same pattern was observed among workers Conclusions This study shows that increasing pain intensity in multiple sites of the body is associated with lower work ability. This was seen for both younger and older workers as well as those with sedentary and physical work. Implications Physical workers with multiple-site pain may especially be at increased risk of the consequences of reduced work ability. Therefore, extra attention is needed and this group may benefit from better targeted preventive measures.

Background Functional tests are widely used to measure performance in patients with chronic musculoskeletal pain. Our objective was to determine the Minimal Clinically Important Differences (MCID) for the 6-min walk test (6MWT), the Steep Ramp Test (SRT), the 1-min stair climbing test (1MSCT), the sit-to-stand test (STS), the Jamar dynamometer test (JAM) and the lumbar Progressive Isoinertial Lifting Evaluation (PILE) in chronic musculoskeletal pain patients. Methods A single-center prospective observational study was conducted in a rehabilitation center. Patients with upper-limb, lower-limb or neck/back lesions were included over a period of 21 months. We used the anchor-based method as a reference method, supplemented by the distribution-based and opinion-based approaches, to determine the MCIDs. Results 838 chronic musculoskeletal pain patients were included. The estimation method and thelesion location had a significant influence on the results. MCIDs were estimated at +75m and +60m for the 6MWT (lower-limb and neck/back lesions, respectively), +18 steps for the 1MSCT (lower-limb and neck/back lesions) and +6kg for the JAM (upper limb lesions). The anchor-based method could not provide valid estimations for the three other scales, but distribution and opinion-based methods provided rough values of MCIDs for the SRT (+39w to +61w), the STS (-5 sec to -7 sec) and the PILE (+4kg to +7kg). Conclusion The above MCID estimations for the 6MWT, 1MSCT and JAM can be used in chronic musculoskeletal pain patients participating in vocational multidisciplinary rehabilitation programs or in therapeutic trials. The use of specific anchors might give better estimations of MCIDs for the three other scales in future research.

Compelling evidence has shown chronic widespread and exaggerated pain experience in chronic musculoskeletal pain (MSKP) conditions. In addition, neuroimaging research has revealed morphological and functional brain alterations in these patients. It is hypothesized that brain alterations play a role in the persistent pain complaints of patients with chronic MSKP. Nevertheless, lack of overview exists regarding the relations between brain alterations and clinical measures of pain. The present systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, to investigate the relations between structural or functional brain alterations, using magnetic resonance imaging scans, and clinical pain measures in patients with chronic MSKP. PubMed, Web of Science, Cinahl, and Cochrane databases were searched. First, the obtained articles were screened according to title and abstract. Second, the screening was on the basis of full-text. Risk of bias in included studies was investigated according to the modified Newcastle-Ottawa Scale. Twenty studies met the inclusion criteria. Moderate evidence shows that higher pain intensity and pressure pain sensitivity are related to decreased regional gray matter (GM) volume in brain regions encompassing the cingulate cortex, the insula, and the superior frontal and temporal gyrus. Further, some evidence exists that longer disease duration in fibro-myalgia is correlated with decreased total GM volume. Yet, inconclusive evidence exists regarding the association of longer disease duration with decreased or increased regional GM volume in other chronic MSKP conditions. Inconclusive evidence was found regarding the direction of the relation of pain intensity and pressure pain sensitivity with microstructural white matter and functional connectivity alterations. In conclusion, preliminary to moderate evidence demonstrates relations between clinical pain measures, and structural and functional connectivity alterations within brain regions involved in somatosensory, affective, and cognitive processing of pain in chronic MSKP. Nevertheless, inconclusive results exist regarding the direction of these relations. Further research is warranted to unravel whether these brain alterations are positively or negatively correlated to clinical pain measures. Perspective: Structural and functional brain alterations within regions involved in somatosensory, affective, and cognitive pain processing play a crucial role in the persistent pain of chronic MSKP patients. Accordingly, these brain alterations have to be taken into account when assessing and treating patients with chronic MSKP. (C) 2016 by the American Pain Society

Chronic musculoskeletal pain is linked with sensitization, and standardized methods for assessment are needed. This study investigated (1) the test-retest reliability of computer-controlled cuff-pressure algometry (pain thresholds and temporal pain summation) on the arm and leg and (2) conditioned pain modulation (CPM) assessed by cuff algometry. The influences of age and gender were evaluated. On 2 different days, cuff pain threshold (cPPT), cuff pain tolerance (cPTT), and temporal summation of pain (TSP) by visual analog scale scores to 10 repeated cuff stimulations at cPTT intensity, as well as pressure pain threshold with handheld pressure algometry, were assessed in 136 healthy subjects. In one session, cuff pain sensitivity was also assessed before and after cold pressor-induced CPM. Good-to-excellent intraclass correlations (0.60-0.90) were demonstrated for manual and cuff algometry, and no systematic bias between sessions was found for cPPT, cPTT, and TSP on the leg and for cPTT and TSP on the arm. Cuff pressure pain threshold and cPTT were higher in men compared with women (P < 0.05). Middle-aged subjects had higher pressure pain threshold, but lower cPPT and cPTT, compared with younger subjects (P < 0.05). Temporal summation of pain was increased in women compared with men (P < 0.05). Cuff algometry was sensitive to CPM demonstrated as increased cPPT and cPTT and reduced TSP (P < 0.05). Reliability and sensitivity of computer-controlled cuff algometry for pain assessment is comparable with manual pressure algometry and constitutes a user-independent method for assessment of pain. Difference in age-related pain sensitivity between manual and cuff algometry should be further investigated.