Sensitivity to Movement-Evoked Pain and Multi-Site Pain are Associated with Work-Disability Following Whiplash Injury: A Cross-Sectional Study

The quality of reporting in randomized controlled trials investigating exercise for individuals with whiplash-associated disorders; a systematic review

BACKGROUND

Whiplash-associated disorders are a common sequela of road traffic accidents. Exercise therapy is considered an effective intervention, and it is recommended for the management of such condition. However, the application of research findings to everyday clinical practice is dependent on sufficient details being reported.

OBJECTIVES

To explore the quality of reporting in studies investigating the effectiveness of exercise for whiplash-associated disorders.

METHODS

A literature search was conducted to identify studies testing the effectiveness of exercise for whiplash-associated disorders. Two reporting checklists were used to evaluate reporting completeness. The median positive scores for each study and overall percentage of positive scores for each item were calculated. Percentage agreement and the Cohen's Kappa coefficient were calculated.

RESULTS

Twenty-one studies were included. According to the Template for Intervention Description and Replication checklist, items were reported appropriately with a median of 29% (range 0-95%, IQR 40.5). The median number of adequately reported items per study was 5 (range 1-10, IQR 3). For the Consensus on Exercise Reporting Template checklist, items were reported appropriately with a median of 29% (range 0-57%, IQR 29). The median number of adequately reported items per study was 4 (range 0-16, IQR 8). Percentage agreement ranged from 57% to 100% while Cohen's Kappa from -0.17 to 1.00.

CONCLUSIONS

The study reveals significant gaps in the quality of reporting in studies investigating exercise for whiplash-associated disorders as both checklists showed a median reporting adequacy of only 29%. Overall, the inter-rater agreement for both checklists was acceptable.

A domain-oriented approach to characterizing movement-evoked pain

Introduction

Movement-evoked pain (MEP) impacts a substantial proportion of US adults living with chronic pain. Evidence suggests that MEP is influenced by numerous biopsychosocial factors and mediated by mechanisms differing from those of spontaneous pain. However, both characteristic and mechanistic knowledge of MEP remain limited, hindering effective diagnosis and treatment.

Objectives

We asked (1) can chronic pain, functional, psychosocial, and behavioral measures be grouped into descriptive domains that characterize MEP? and (2) what relationships exist between biopsychosocial factors across multiple domains of MEP?

Methods

We formed 6 characteristic domains from 46 MEP-related variables in a secondary analysis of data from 178 individuals (aged 45-85 years) with knee pain. Ratings of pain during 3 functional activities (ie, Balance, Walking, Chair Stand) were used as primary MEP variables. Pearson correlations were calculated to show linear relationships between all individual domain variables. Relationships between variables were further investigated through weighted correlation network analysis.

Results

We observed a unique combination of pain characteristics associated with MEP apart from general pain. Notably, minutes doing physical activity were inversely associated with multiple variables within 4 of the 6 domains. Weighted correlation network analysis largely supported our classification of MEP domains. Additional interdomain relationships were observed, with the strongest existing between MEP, Mechanical Pain, and Multiple Pain Characteristics and Symptoms. Additional relationships were observed both within and between other domains of the network.

Conclusion

Our analyses bolster fundamental understanding of MEP by identifying relevant mechanistic domains and elucidating biopsychosocial and interdomain relationships.

Association between multisite musculoskeletal pain and disability trajectories among community-dwelling older adults

BACKGROUND

Pain is linked to disability, but how multisite musculoskeletal pain leads to disability over time is not well elaborated.

OBJECTIVE

To examine the associations of multisite musculoskeletal pain with disability among a nationally representative cohort.

DESIGN

We used data from the National Health and Aging Trends Study (NHATS) 2015-22. Disability was assessed by basic activities of daily living (ADL) and instrumental activities of daily living (IADL).

PARTICIPANTS

A total of 5557 individuals with multisite musculoskeletal pain dwelling in the community were included in this study.

METHODS

Group-based trajectory models were applied to identify distinct profiles of disability in ADL and IADL. Design-based logistic regressions were used to examine associations among multisite musculoskeletal pain, disability, and dual trajectory group memberships, adjusted for sociodemographic, health status, behavioral, and mental characteristics.

RESULTS

Persons who experienced multisite musculoskeletal pain were at higher risk of disability in ADL and IADL. We identified five heterogeneous disability trajectories and named them based on baseline levels and rates of increase over time. Approximately, 52.42% of older adults with multisite musculoskeletal pain were in trajectories with ADL and IADL declines, and 33.60% experienced a rapid decline. Multisite musculoskeletal pain was associated with elevated relative risk for the adverse disability trajectories, which generally increases with multisite musculoskeletal pain frequency and number of sites.

CONCLUSIONS

Persons with multisite musculoskeletal pain had a higher risk of disability. It is essential to adopt effective pain management strategies to maintain the independent living ability of older adults and to realize active aging.

Are biomarkers associated with sensitivity to physical activity?

BACKGROUND

Activity-based treatments play an integral role in managing musculoskeletal conditions including low back pain. However, while therapeutic exercise has been shown to reduce pain in such conditions, certain individuals experience a paradoxical pain increase in response to exercise. The physiological processes underlying this sensitivity to physical activity (SPA) are not fully understood, however stress and inflammation have been shown to contribute to SPA. The present cross-sectional study investigated whether physiological indicators of stress (cortisol) and inflammation (IL-6) help explain SPA.

METHODS

Twenty-seven patients with chronic low back pain and 21 healthy controls completed a 1-h exercise session of standardized physical tasks. SPA was calculated from the difference between post- and pre-exercise pain levels. Participant's saliva was collected at several timepoints for cortisol and IL-6 levels quantification. Their waking cortisol response was calculated to reflect their cortisol regulation. Reactivity of IL-6 and cortisol was calculated to reflect changes in these measures during exercise.

RESULTS

IL-6 reactivity was significantly and positively correlated with SPA among participants with low back pain. In contrast, neither cortisol waking response nor cortisol reactivity was significantly correlated within the low back pain group. No significant differences in IL-6 reactivity, cortisol reactivity or cortisol waking response were observed.

CONCLUSION

These findings are the first to link SPA to an objective biomarker among people with low back pain. These findings help describe the physiological mechanisms of SPA and can support new clinical research that targets the inflammatory response of patients with chronic low-back pain and elevated SPA.

SIGNIFICANCE

This study reveals a correlation between SPA and an objective salivary biomarker of IL-6 in people with low back pain, improving our understanding of this clinically relevant subjective experience.

Test-retest reliability of movement-evoked pain and sensitivity to movement-evoked pain in patients with rotator cuff-related shoulder pain

BACKGROUND

The number of researchers and clinicians using movement-evoked pain and sensitivity to movement-evoked pain to assess shoulder pain has increased. However, the intrarater test-retest reliability of movement-evoked pain and sensitivity to movement-evoked pain in people with rotator cuff-related shoulder pain (RCRSP) is still unknown.

OBJECTIVE

We examined the intrarater test-retest reliability of movement-evoked pain and sensitivity to movement-evoked pain in participants with RCRSP.

METHODS

Seventy-four participants with RCRSP performed five trials of active shoulder abduction to elicit pain under two experimental conditions: active shoulder abduction to the onset of pain and maximum range of motion (ROM). The primary outcome measures were pain intensity and ROM. Test-retest reliability of movement-evoked pain and sensitivity to movement-evoked pain was examined using intraclass correlation coefficient (ICC3,1) and minimal detectable change (MDC90).

RESULTS

The reliability of movement-evoked pain under both experimental conditions was good to excellent (ICC: 0.81 to 0.95), while the reliability of sensitivity to movement-evoked pain was poor in both conditions (ICC≤0.45). The MDC90 for pain intensity was 1.6 and 1.8 during shoulder abduction to the onset of pain and maximum ROM, respectively. The MDC90 for ROM was 17.5° and 11.2° during shoulder abduction to the onset of pain and maximum ROM condition, respectively.

CONCLUSION

This study confirms movement-evoked pain testing during active shoulder abduction to the onset of pain or maximum ROM condition is reliable to assess pain associated with movement in patients with RCRSP. The minimal detectable change score of movement-evoked pain can guide clinicians and researchers on how to interpret changes in these outcomes.

Perceived Injustice as a Determinant of the Severity of Post-traumatic Stress Symptoms Following Occupational Injury

BACKGROUND

The present study assessed the role of perceived injustice in the experience and persistence of post-traumatic stress symptoms (PTSS) following work-related musculoskeletal injury.

METHODS

The study sample consisted of 187 individuals who were absent from work as a result of a musculoskeletal injury. Participants completed measures of pain severity, perceived injustice, catastrophic thinking, post-traumatic stress symptoms, and disability on three occasions at three-week intervals.

RESULTS

Consistent with previous research, correlational analyses revealed significant cross-sectional relations between pain and PTSS, and between perceived injustice and PTSS. Regression analysis on baseline data revealed that perceived injustice contributed significant variance to the prediction of PTSS, beyond the variance accounted for by pain severity and catastrophic thinking. Sequential analyses provided support for a bi-directional relation between perceived injustice and PTSS. Cross-lagged regression analyses showed that early changes in perceived injustice predicted later changes in PTSS and early changes in PTSS predicted later changes in perceived injustice.

CONCLUSIONS

Possible linkages between perceived injustice and PTSS are discussed. The development of effective intervention techniques for targeting perceptions of injustice might be important for promoting recovery of PTSS consequent to musculoskeletal injury.

Activity-related pain predicts pain and functional outcomes in people with knee osteoarthritis: A longitudinal study

Knee Osteoarthritis (OA) is a prevalent musculoskeletal condition, commonly resulting in pain and disability. However, pain and disability in this population are poorly related with the degree of structural joint damage. Underlying pain mechanisms, including activity-related pain and sensitization assessed via Quantitative Sensory Testing (QST), may better predict pain and functional outcomes of those with knee OA. Therefore, the aim of this study was to explore whether activity-related pain and sensitization assessed via QST predict future pain, function, fatigue, physical performance and quality of life outcomes in those living in the community with knee OA. Eighty-six participants with knee OA were recruited in Dunedin, New Zealand. Those eligible to participate underwent baseline testing including QST as well as measures of activity-related pain including Movement-evoked Pain (MEP) and Sensitivity to Physical Activity (SPA). Outcome measures exploring pain, function, fatigue and quality of life outcomes were collected at baseline, and two follow-up periods (two and nine weeks). Univariable linear regression models were developed followed by multivariable linear regression models for each prognostic marker adjusting for age, gender, BMI, OA duration, baseline pain intensity and socioeconomic status. Activity-related measures of pain, including MEP and SPA, demonstrated predictive associations with pain and functional outcomes prospectively in those with knee OA. Therefore, those demonstrating activity-related pain are at future risk of greater pain, disability and reduced quality of life. Larger, externally validated longitudinal studies are required which include individuals with more severe knee OA.

Factors associated with disability and pain intensity in patients with complex regional pain syndrome

PURPOSE

To examine the associations between psychological factors (pain catastrophizing, pain-related anxiety, and fear of pain) and level of pain and disability in patients with complex regional pain syndrome (CRPS).

METHODS

One hundred and two patients with CRPS were recruited from tertiary care centers with the different upper limb injuries were evaluated for pain, disability, and psychological factors. Patients completed the Disabilities of the Arm, Shoulder, and Hand (DASH) Questionnaire, Patient Rated Wrist Evaluation (PRWE), Pain Catastrophizing Scale (PCS), Tampa Scale of Kinesiophobia (TSK-11), and Depression, Anxiety, and Stress Scale (DASS). The associations of pain and disability with presence of these behavioral and mental health factors were examined using bivariate and multivariable analyses. These models were adjusted for age, sex, injured dominant hand, and previous surgery.

RESULTS

A higher pain catastrophizing score (β = 0.55, p = 0.00) was associated with greater disability. A higher pain catastrophizing score (β = 0.35, p = 0.001) and female gender (β = 0.24, p = 0.01) were associated with greater pain at rest (PAR). A higher pain catastrophizing score and having a surgical history were associated with greater pain with movement (β = 0.25, p = 0.02). Scores of ≥18.5 in PCS, ≥57.5 on TSK, and ≥15.5 on DASS were associated with higher risk of experiencing pain and disability.

CONCLUSIONS

Pain catastrophizing, female sex, and surgical intervention are associated with poor outcomes. Physiologic, psychological factors, and treatment factors interact to influence outcomes. The results of this study further validate the associations of chronic pain and disability with pain catastrophizing in patients with CRPS. The novel finding of this study is introducing cut-off scores for TSK, PCS, and DASS as a screening tool to predict pain, functional limitations.Implication for rehabilitationPain catastrophizing has a vital role in the magnitude of disability and pain in patients with CRPS.The novel finding of this paper was the cut-off scores on the psychological evaluations that can enable using them as screening tool for bad outcomes in patients with CRPS.Cut off scores from different psychological evaluations can be used as a yellow flag for clinician's for detecting patients with increased risk of pain and disability.The identification of a cut-off can also have implications for implementing change in clinical practice by identifying the need for early and intensive interventions.

Do psychological factors relate to movement-evoked pain in people with musculoskeletal pain? A systematic review and meta-analysis

BACKGROUND

A growing body of evidence has demonstrated the importance of implementing movement-evoked pain in conventional pain assessments, with a significant role for psychological factors being suggested. Whether or not to include these factors in the assessment of movement-evoked pain has not yet been determined.

OBJECTIVES

The aim of this systematic review is to explore the association between psychological factors and movement-evoked pain scores in people with musculoskeletal pain.

METHODS

For this systematic review with meta-analysis, four electronic databases (PubMed, Medline, WOS, and Scopus) were searched. Cross-sectional studies, longitudinal cohort studies, and randomized controlled trials investigating the association between movement-evoked pain and psychological factors in adults with musculoskeletal pain were considered. Meta-analysis was conducted for outcomes with homogeneous data from at least 2 studies. Fischer-Z transformations were used as the measure of effect. Quality of evidence was assessed using the National Institutes of Health's Quality assessment tool for observational cohort and cross-sectional studies and Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.

RESULTS

Meta-analyses and grading the quality of evidence revealed moderate evidence for a relation between movement-evoked pain and depressive symptoms (Fisher-z=0.27; 95%CI: 0.17, 0.36; 5 studies (n=440)), pain-related fear (Fisher-z=0.35; 95%CI: 0.26, 0.44; 6 studies (n=492)), and pain catastrophizing (Fisher-z=0.47; 95%CI: 0.36, 0.58; 4 studies (n=312)) in people with musculoskeletal pain.

CONCLUSIONS

Movement-evoked pain is weakly to moderately associated to depressive symptoms, pain-related fear, and pain catastrophizing in people with musculoskeletal pain.

The Impact of Musculoskeletal Injuries Sustained in Road Traffic Crashes on Work-Related Outcomes: A Systematic Review

Musculoskeletal injuries occur frequently after road traffic crashes (RTCs), and the effect on work participation is not fully understood. The primary aim of this review was to determine the impact of sustaining a musculoskeletal injury during an RTC on the rate of return to work (RTW), sick leave, and other work outcomes. The secondary aim was to determine factors associated with these work-related outcomes. An electronic search of relevant databases to identify observational studies related to work and employment, RTC, and musculoskeletal injuries was conducted. Where possible, outcome data were pooled by follow-up period to answer the primary aim. Fifty-three studies were included in this review, of which 28 were included in meta-analyses. The pooled rate of RTW was 70% at 1 month, 67% at 3 months, 76% at 6 months, 83% at 12 months, and 70% at 24 months. Twenty-seven percent of participants took some sick leave by one month follow-up, 13% by 3 months, 23% by 6 months, 36% by 12 months, and 22% by 24 months. Most of the factors identified as associated with work outcomes were health-related, with some evidence also for sociodemographic factors. While 70% of people with RTC-related musculoskeletal injury RTW shortly after accident, many still have not RTW two years later.

Return to work a bumpy road: a qualitative study on experiences of work ability and work situation in individuals with chronic whiplash-associated disorders

Background

Work resumption is a big challenge in the rehabilitation process for individuals with whiplash-associated disorders (WAD). To better meet the needs of individuals with WAD in their return to work process, more knowledge on their experiences and perspectives is needed. The aim of this study was to explore the experiences of work ability and the work situation of individuals who participated in a neck-specific exercise programme for chronic WAD.

Methods

This qualitative study has an exploratory and descriptive design based on data collected through open-ended interviews with 17 individuals with chronic WAD. Data were analysed inductively using conventional content analysis.

Results

Analysis of the data yielded the following five categories related to the participants’ narratives on their experiences of work ability and their work situation: Return to work – a process of setbacks and bureaucracy; The need to be understood by health care professionals, and to receive a treatment plan; Individual resources are important for work ability; The consequences of reduced work ability; and Working conditions are important for work ability.

Conclusion

Individuals with chronic WAD often struggle to return to work. Emotional and practical support from stakeholders is imperative and needs to be strengthened. Participating in a neck-specific exercise programme, including being acknowledged and receiving information about WAD, could positively affect the work ability of WAD sufferers. This study has provided management strategies to improve the ability to work for individuals with chronic WAD, and highlights the need to incorporate a healthy and sustainable return to work in the rehabilitation of individuals with WAD, thereby making their return to work a success.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10821-w.

Toward Understanding Movement-evoked Pain (MEP) and its Measurement: A Scoping Review

OBJECTIVE

Individuals with chronic pain conditions often report movement as exacerbating pain. An increasing number of researchers and clinicians have recognized the importance of measuring and distinguishing between movement-evoked pain (MEP) and pain at rest as an outcome. This scoping review maps the literature and describes MEP measurement techniques.

MATERIALS AND METHODS

The scoping review utilized 6 databases to identify original studies that targeted pain or movement-related outcomes. Our search returned 7322 articles that were screened by title and abstract by 2 reviewers. The inclusion criteria focused on the measurement of MEP before, during, and after movement tasks in adults with chronic pain. Studies of children below 18 years of age or with nonhuman animals, case studies, qualitative studies, book chapters, cancer-related pain, non-English language, and abstracts with no full publish text were excluded from the study.

RESULTS

Results from 38 studies revealed great variation in the measurement of MEP, while almost all of the studies did not provide an explicit conceptual or operational definition for MEP. In addition, studies collectively illuminated differences in MEP compared with rest pain, movement provocation methods, and pain intensity as the primary outcome.

DISCUSSION

These results have clinically significant and research implications. To advance the study of MEP, we offer that consistent terminology, standardized measurement (appropriate for pain type/population), and clear methodological processes be provided in research publications. On the basis of the findings, we have put forth a preliminary definition of MEP that may benefit from the continued scholarly dialog.

Cortical dynamics of movement-evoked pain in chronic low back pain

KEY POINTS

Cortical activity underlying movement-evoked pain is not well understood, despite being a key symptom of chronic musculoskeletal pain. We combined high-density electroencephalography with a full-body reaching protocol in a virtual reality environment to assess cortical activity during movement-evoked pain in chronic low back pain. Movement-evoked pain in individuals with chronic low back pain was associated with longer reaction times, delayed peak velocity and greater movement variability. Movement-evoked pain was associated with attenuated disinhibition in prefrontal motor areas, as evidenced by an attenuated reduction in beta power in the premotor cortex and supplementary motor area.

ABSTRACT

Although experimental pain alters neural activity in the cortex, evidence of changes in neural activity in individuals with chronic low back pain (cLBP) remains scarce and results are inconsistent. One of the challenges in studying cLBP is that the clinical pain fluctuates over time and often changes during movement. The goal of the present study was to address this challenge by recording high-density electroencephalography (HD-EEG) data during a full-body reaching task to understand neural activity during movement-evoked pain. HD-EEG data were analysed using independent component analyses, source localization and measure projection analyses to compare neural oscillations between individuals with cLBP who experienced movement-evoked pain and pain-free controls. We report two novel findings. First, movement-evoked pain in individuals with cLBP was associated with longer reaction times, delayed peak velocity and greater movement variability. Second, movement-evoked pain was associated with an attenuated reduction in beta power in the premotor cortex and supplementary motor area. Our observations move the field forward by revealing attenuated disinhibition in prefrontal motor areas during movement-evoked pain in cLBP.

Comparing Novel and Existing Measures of Sensitivity to Physical Activity Among People With Chronic Musculoskeletal Pain: The Importance of Tailoring Activity to Pain

OBJECTIVES

Increasing pain during physical activity is an important, but often poorly assessed, barrier to engaging in activity-based rehabilitation among people with chronic musculoskeletal pain. Preliminary work has addressed this problem by developing new clinical measures of sensitivity to physical activity (SPA). Indices of SPA are generated by evaluating how pain changes in relation to brief physical tasks. Three strategies have been identified for structuring SPA-related physical tasks (self-paced, standardized, and tailored). This cross-sectional study aimed to comparatively estimate the extent of the 3 SPA tasks' evoked pain responses, predictive value of pain severity and pain interference, and their underlying psychological and sensory constructs, among 116 adults with chronic musculoskeletal pain.

MATERIALS AND METHODS

Testing included questionnaires, quantitative sensory testing, and the 3 SPA measures (self-paced, standardized, and tailored). The primary analysis estimated the predictive value of each SPA measure for pain severity and pain interference. Correlational analyses were first conducted between all variables of interest to determine what variables will be included in the hierarchical regression analysis, which in turn was conducted for each outcome.

RESULTS

Analyses revealed that the tailored SPA index was most effective at evoking activity-related pain, was uniquely associated with temporal summation of pain, and was a unique predictor of pain and pain-related interference, even when controlling for established psychological and sensory risk factors.

DISCUSSION

This study further emphasizes SPA as an important and unique attribute of the pain experience and reveals the added value of using a tailored approach to assess SPA.

Task-Specific Sensitivity in Physical Function Testing Predicts Outcome in Patients With Low Back Pain

OBJECTIVE

To investigate the prognostic value of task-specific sensitivity in patients with low back pain by exploring whether task-specific sensitivity during physical function testing was associated with self-reported change in pain and disability.

DESIGN

Prospective cohort study nested in a randomized controlled trial.

METHODS

The study included 260 patients with low back pain, referred for evaluation in a secondary care setting. All patients completed questionnaires and underwent clinical examination by a physical therapist. Patients rated their pain intensity before and after completing a test battery measuring physical function and were classified into 4 categories-worse, unchanged, better, or no pain-depending on their pain response. At 3-month follow-up, outcomes were obtained by a postal questionnaire.

RESULTS

Task-specific sensitivity significantly predicted pain, after adjusting for known prognostic factors. Patients in the no pain, better, and unchanged groups improved their pain score significantly more than patients in the worse pain group. Patients in the no pain group also improved their disability score significantly more compared to patients in the worse pain group, after adjusting for known prognostic factors.

CONCLUSION

Task-specific sensitivity predicted pain intensity after 3 months in patients with low back pain. The prognostic value appears limited with respect to disability. J Orthop Sports Phys Ther 2020;50(4):206-213. Epub 30 Oct 2019. doi:10.2519/jospt.2020.8953.

Pain resilience moderates the influence of negative pain beliefs on movement-evoked pain in older adults

Negative pain beliefs are associated with adverse pain outcomes; however, less is known regarding how positive, adaptive factors influence pain and functioning. These relationships are especially important to examine in older adults with pain, given increased disability and functional limitations in this population. We investigated whether pain resilience moderated the relationships between negative pain beliefs (fear-avoidance, pain catastrophizing) and pain outcomes (functional performance, movement-evoked pain) in sixty older adults with low back pain. Higher pain resilience was associated with lower fear-avoidance (p < .05) and pain catastrophizing (p = .05). After controlling for demographic variables, higher fear-avoidance (p = .03) and catastrophizing (p = .03) were associated with greater movement-evoked pain in individuals with low pain resilience, but not among those high in resilience. No significant moderation effects were observed for functional performance. Resilience may attenuate the relationship between negative psychological processes and pain-related disability, highlighting the need for interventions that enhance pain resilience in older adults.

Exercise-Induced Hypoalgesia in Pain-Free and Chronic Pain Populations: State of the Art and Future Directions

Exercise is considered an important component of effective chronic pain management and it is well-established that long-term exercise training provides pain relief. In healthy, pain-free populations, a single bout of aerobic or resistance exercise typically leads to exercise-induced hypoalgesia (EIH), a generalized reduction in pain and pain sensitivity that occurs during exercise and for some time afterward. In contrast, EIH is more variable in chronic pain populations and is more frequently impaired; with pain and pain sensitivity decreasing, remaining unchanged or, in some cases, even increasing in response to exercise. Pain exacerbation with exercise may be a major barrier to adherence, precipitating a cycle of physical inactivity that can lead to long-term worsening of both pain and disability. To optimize the therapeutic benefits of exercise, it is important to understand how EIH works, why it may be impaired in some people with chronic pain, and how this should be addressed in clinical practice. In this article, we provide an overview of EIH across different chronic pain conditions. We discuss possible biological mechanisms of EIH and the potential influence of sex and psychosocial factors, both in pain-free adults and, where possible, in individuals with chronic pain. The clinical implications of impaired EIH are discussed and recommendations are made for future research, including further exploration of individual differences in EIH, the relationship between exercise dose and EIH, the efficacy of combined treatments and the use of alternative measures to quantify EIH. PERSPECTIVE: This article provides a contemporary review of the acute effects of exercise on pain and pain sensitivity, including in people with chronic pain conditions. Existing findings are critically reviewed, clinical implications are discussed, and recommendations are offered for future research.

Race/Ethnicity Moderates the Association Between Psychosocial Resilience and Movement-Evoked Pain in Knee Osteoarthritis

Objective

Racial/ethnic disparities in pain are well‐recognized, with non‐Hispanic blacks (NHBs) experiencing greater pain severity and pain‐related disability than non‐Hispanic whites (NHWs). Although numerous risk factors are posited as contributors to these disparities, there is limited research addressing how resilience differentially influences pain and functioning across race/ethnicity. Therefore, this study examined associations between measures of psychosocial resilience, clinical pain, and functional performance among adults with knee osteoarthritis (OA), and assessed the moderating role of race/ethnicity on these relationships.

Methods

In a secondary analysis of the Understanding Pain and Limitations in Osteoarthritic Disease (UPLOAD‐2) study, 201 individuals with knee OA (NHB = 105, NHW = 96) completed measures of resilience (ie, trait resilience, optimism, positive well‐being, social support, positive affect) and clinical pain, as well as a performance‐based measure assessing lower‐extremity function and movement‐evoked pain.

Results

Bivariate analyses showed that higher levels of psychosocial resilience were associated with lower clinical pain and disability and more optimal physical functioning. NHBs reported greater pain and disability, poorer lower‐extremity function, and higher movement‐evoked pain compared with NHWs; however, measures of psychosocial resilience were similar across race/ethnicity. In moderation analyses, higher optimism and positive well‐being were protective against movement‐evoked pain in NHBs, whereas higher levels of positive affect were associated with greater movement‐evoked pain in NHWs.

Conclusion

Our findings underscore the importance of psychosocial resilience on OA‐related pain and function and highlight the influence of race/ethnicity on the resilience‐pain relationship. Treatments aimed at targeting resilience may help mitigate racial/ethnic disparities in pain.

Validation of an index of Sensitivity to Movement-Evoked Pain in patients with whiplash injuries

Introduction: Sensitivity to Movement-Evoked Pain is a pain summation phenomenon identified in various chronic pain populations. Objectives: This study investigated the validity of a procedure used to assess pain summation in response to a repeated lifting task in individuals with whiplash injuries. Methods: Sixty-five participants completed measures of pain severity and duration, Temporal Summation (TS) of pinprick pain, pain catastrophizing and fear of movement, and work-related disability before lifting a series of 18 weighted canisters. An index of Sensitivity to Movement-Evoked Pain was computed as the increase in pain reported by participants over successive lifts of the weighted canisters. An index of TS was computed by dividing the pain reported in response to the final pinprick by the pain reported in response to the 1st pinprick in a train of 10 pinpricks. Results: Analyses replicated previous findings showing a repetitive lifting task-induced pain summation in approximately 20% to 25% of a sample of individuals with whiplash injuries. Analyses also revealed significant correlations between SMEP, TS, and pain-related psychological variables. Hierarchical regression analyses showed that TS and pain catastrophizing made significant unique contributions to the prediction of SMEP. These findings join a growing body of research on movement-evoked pain in persistent spinal pain conditions. Conclusion: The repeated lifting task used in this study successfully induced pain summation in a group of patients with whiplash injuries.