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Racism is an established health determinant across the world. In this 3-part series, we argue that a disregard of how racism manifests in pain research practices perpetuates pain inequities and slows the progression of the field. Our goal in part-1 is to provide a historical and theoretical background of racism as a foundation for understanding how an antiracism pain research framework - which focuses on the impact of racism, rather than “race,” on pain outcomes - can be incorporated across the continuum of pain research. We also describe cultural humility as a lifelong self-awareness process critical to ending generalizations and successfully applying antiracism research practices through the pain research continuum. In part-2 of the series, we describe research designs that perpetuate racism and provide reframes. Finally, in part-3, we emphasize the implications of an antiracism framework for research dissemination, community-engagement practices and diversity in research teams. Through this series, we invite the pain research community to share our commitment to the active process of antiracism, which involves both self-examination and re-evaluation of research practices shifting our collective work towards eliminating racialized injustices in our approach to pain research. Perspective: We call on the pain community to dismantle racism in our research practices. As the first paper of the 3-part series, we introduce dimensions of racism and its effect on pain inequities. We also describe the imperative role of cultural humility in adopting antiracism pain research practices.

Fibromyalgia (FM) is a chronic pain disorder characterized by chronic widespread musculoskeletal pain (CWP), resting pain, movement-evoked pain (MEP), and other somatic symptoms that interfere with daily functioning and quality of life. In clinical studies, this symptomology is assessed, while preclinical models of CWP are limited to nociceptive assays. The aim of the study was to investigate the human-to-model translatability of clinical behavioral assessments for spontaneous (or resting) pain and MEP in a preclinical model of CWP. For preclinical measures, the acidic saline model of FM was used to induce widespread muscle pain in adult female mice. Two intramuscular injections of acidic or neutral pH saline were administered following baseline measures, 5 days apart. An array of adapted evoked and spontaneous pain measures and functional assays were assessed for 3 weeks. A novel paradigm for MEP assessment showed increased spontaneous pain following activity. For clinical measures, resting and movement-evoked pain and function were assessed in adult women with FM. Moreover, we assessed correlations between the preclinical model of CWP and in women with fibromyalgia to examine whether similar relationships between pain assays that comprise resting and MEP existed in both settings. For both preclinical and clinical outcomes, MEP was significantly associated with mechanical pain sensitivity. Preclinically, it is imperative to expand how the field assesses spontaneous pain and MEP when studying multi-symptom disorders like FM. Targeted pain assessments to match those performed clinically is an important aspect of improving preclinical to clinical translatability of animal models.

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.

OBJECTIVES: Peripherally directed treatments (targeted exercise, surgery) can reduce, but not fully eliminate, pain for up to 40% of patients with Achilles tendinopathy. The objectives of the present study were (1) to identify indicators of altered central processing in participants with Achilles tendinopathy compared to controls, and (2) to determine which indicators of altered central processing would persist after a local anesthetic injection in patients with Achilles tendinopathy. DESIGN: Mechanistic clinical trial. METHODS: Forty-six adults (23 with chronic Achilles tendinopathy, 23 matched controls) repeated (1) a movement-evoked pain rating, (2) motor performance assessment, (3) pain psychology questionnaires, and (4) quantitative sensory testing. Participants with Achilles tendinopathy received a local anesthetic injection before repeat testing and controls did not. Mixed-effects analyses of variance examined the effects of group, time, and group by time. RESULTS: The Achilles tendinopathy group had movement-evoked pain, motor dysfunction, and higher pain psychological factors (pain catastrophizing, kinesiophobia) compared to controls (P.05). In those with Achilles tendinopathy, local anesthetic injection eliminated pain and normalized the observed deficits in heel-raise performance and pain catastrophizing (group-by-time effect, P.05). CONCLUSION: People with Achilles tendinopathy had elevated pain psychological factors and motor dysfunction but no signs of nociplastic pain with quantitative sensory testing. Removal of nociceptive input normalized movement-evoked pain and some indicators of altered central processing (motor dysfunction, pain catastrophizing), but not kinesiophobia.

OBJECTIVE Fibromyalgia (FM) is characterized by pain and fatigue, particularly during physical activity. Transcutaneous electrical nerve stimulation (TENS) activates endogenous pain inhibitory mechanisms. This study was undertaken to investigate if using TENS during activity would improve movement-evoked pain and other patient-reported outcomes in women with FM. METHODS Participants were randomly assigned to receive active TENS (n = 103), placebo TENS (n = 99), or no TENS (n = 99) and instructed to use it at home during activity 2 hours each day for 4 weeks. TENS was applied to the lumbar and cervicothoracic regions using a modulated frequency (2-125 Hz) at the highest tolerable intensity. Participants rated movement-evoked pain (primary outcome measure) and fatigue on an 11-point scale before and during application of TENS. The primary outcome measure and secondary patient-reported outcomes were assessed at baseline (time of randomization) and at 4 weeks. RESULTS After 4 weeks, a greater reduction in movement-evoked pain was reported in the active TENS group versus the placebo TENS group (group mean difference -1.0 [95% confidence interval -1.8, -0.2]; P = 0.008) and versus the no TENS group (group mean difference -1.8 [95% confidence interval -2.6, -1.0]; P < 0.0001). A reduction in movement-evoked fatigue was also reported in the active TENS group versus the placebo TENS group (group mean difference -1.4 [95% confidence interval -2.4, -0.4]; P = 0.001) and versus the no TENS group (group mean difference -1.9 [95% confidence interval -2.9, -0.9]; P =

Fibromyalgia (FM) is a chronic pain disorder characterized by chronic widespread musculoskeletal pain (CWP), tenderness, and fatigue, which interferes with daily functioning and quality of life. In clinical studies, this symptomology is assessed, while preclinical models of CWP are limited to nociceptive assays. The aim of the study was to investigate the human-to-model translatability of clinical behavioral assessments for pain and muscle function in a preclinical model of CWP. We assessed correlations between pain behaviors and muscle function in a preclinical model of CWP and in women with fibromyalgia to examine whether similar relationships between outcomes existed in both settings, for usability of clinical assays in model systems. For preclinical measures, the acidic saline model of FM which induces widespread muscle pain, was used in adult female mice. Two gastrocnemius injections of acidic or physiological pH saline were given following baseline measures, five days apart. An array of adapted pain measures and functional assays were assessed for three weeks. For clinical measures, pain and functional assays were assessed in adult women with FM. For both preclinical and clinical outcomes, movement-evoked pain (MEP) was associated with mechanical pain sensitivity. Mechanical sensitivity was correlated to shifts in weight-bearing preclinically and was predictive of functionality in patients. Preclinically, it is imperative to expand how the field assesses pain behaviors when studying multi- symptom disorders like FM. Targeted pain assessments to match those performed clinically is an important aspect of improving preclinical to clinical translatability of animal models.SummaryPreclinical assessments of chronic musculoskeletal pain recapitulate several outcome measures for clinical assessment of patients with FM, particularly prolonged resting pain, and MEP.

This second paper in a 3-part series on antiracism in pain research across the translational spectrum focuses on study design factors. Although objectivity is a cornerstone value of science, subjectivity is embedded in every step of the research process as investigators make choices about who they collaborate with, which research questions they ask, how they recruit participants, which research tools they use, and how they analyze and interpret data. We present theory and evidence from disciplines such as sociology, medical anthropology, statistics, and public health to discuss 4 common study design factors, including 1) the dominant biomedical narrative of pain that restricts funding and exploration of social indicators of pain, 2) low diversity and inclusion in pain research enrollment that restricts generalizability to racialized groups, 3) the use of “race” or “ethnicity” as a statistical variable and proxy for lived experiences (eg, racism, resilience), and 4) limited modeling in preclinical research for the impact of social factors on pain physiology. The information presented in this article is intended to start conversations across stakeholders in the pain field to explore how we can come together to adopt antiracism practices in our work at large to achieve equity for racialized groups. Perspective: This is the second paper in a 3-part series on antiracism in pain research. This part identifies common study design factors that risk hindering progress toward pain care equity. We suggest reframes using an antiracism framework for these factors to encourage all pain investigators to collectively make strides toward equity.

Background Everyday experiences with racial (RD) and weight discrimination (WD) are risk factors for chronic pain in ethnically diverse adults with obesity. However, the individual or combined effects of RD and WD on pain in adults with obesity is not well understood. There are gender differences and sexual dimorphisms in nociception and pain, but the effect of gender on relationships between RD, WD, and pain outcomes in ethnically diverse adults with obesity is unclear. Thus, the purposes of this study were to: 1) examine whether RD and WD are associated with pain intensity and interference, and 2) explore gender as a moderator of the associations between RD, WD, and pain. Methods This is a baseline data analysis from a randomized, controlled clinical trial of a lifestyle weight-management intervention. Eligible participants were English or Spanish-speaking (ages 18–69 years) and had either a body mass index of ≥30 kg/m2 or ≥ 25 kg/m2 with weight-related comorbidity. RD and WD were measured using questions derived from the Experiences of Discrimination questionnaire (EOD). Pain interference and intensity were measured using the PROMIS 29 adult profile V2.1. Linear regression models were performed to determine the associations between WD, RD, gender, and pain outcomes. Results Participants (n = 483) reported mild pain interference (T-score: 52.65 ± 10.29) and moderate pain intensity (4.23 ± 3.15). RD was more strongly associated with pain interference in women (b = .47, SE = .08, p b = .14, SE = .07, p = .06). Also, there were no significant interaction effects between RD and gender on pain intensity, or between WD and gender on pain interference or pain intensity. Conclusions Pain is highly prevalent in adults with obesity, and is impacted by the frequencies of experiences with RD and WD. Further, discrimination against adults with obesity and chronic pain could exacerbate existing racial disparities in pain and weight management. Asking ethnically diverse adults with obesity about their pain and their experiences of RD and WD could help clinicians make culturally informed assessment and intervention decisions that address barriers to pain relief and weight loss. Trial registration NCT03006328

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.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 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.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.

Fibromyalgia (FM) is characterized by widespread chronic pain, fatigue, and somatic symptoms. The influence of phenotypic changes in monocytes on symptoms associated with FM is not fully understood. The primary aim of this study was to take a comprehensive whole-body to molecular approach in characterizing relationships between monocyte phenotype and FM symptoms in relevant clinical populations. Lipopolysaccharide-evoked and spontaneous secretion of IL-5 and other select cytokines from circulating monocytes was higher in women with FM compared to women without pain. In addition, greater secretion of IL-5 was significantly associated with pain and other clinically relevant psychological and somatic symptoms of FM. Furthermore, higher levels of pain and pain-related symptoms were associated with a lower percentage of intermediate monocytes (CD14++/CD16+) and a greater percentage of nonclassical monocytes (CD14+/CD16++) in women with FM. Based on findings from individuals with FM, we examined the role of IL-5, an atypical cytokine secreted from monocytes, in an animal model of widespread muscle pain. Results from the animal model show that IL-5 produces analgesia and polarizes monocytes toward an anti-inflammatory phenotype (CD206+). Taken together, our data suggest that monocyte phenotype and their cytokine profiles are associated with pain-related symptoms in individuals with FM. Furthermore, our data show that IL-5 has a potential role in analgesia in an animal model of FM. Thus, targeting anti-inflammatory cytokines such as IL-5 secreted by circulating leukocytes could serve as a promising intervention to control pain and other somatic symptoms associated with FM.

This study examined whether depression and anxiety differentially relate to fatigue, sleep disturbance, pain catastrophizing, fear of movement, and pain severity in women with fibromyalgia. Baseline data from the Fibromyalgia Activity Study with Transcutaneous Electrical Nerve Stimulation were analyzed. Of 191 participants, 50 percent reported high anxiety and/or depression (17% high anxiety, 9% high depression, and 24% both). Fatigue and sleep impairment were associated with high depression ( p

Aims: To determine if participants can reduce foot progression angle (FPA), and if FPA reduction decreases regional plantar stresses and forces in individuals with diabetes. Methods: Design: Three-group cross-sectional design with repeated measures. Subjects: Twenty-eight participants either with diabetes mellitus (DM), diabetes and peripheral neuropathy with (DMPN+NPU) or without a prior history of ulceration (DMPN-NPU) were studied. Intervention: Participants were first instructed to walk over a 3.6 m walkway at their preferred FPA, and then to walk with their foot aligned parallel with the line of gait progression at their self-selected speed. Dynamic plantar kinetics in six masked regions were collected using an EMED-ST-P-2 pedobarograph. Main measures: Primary outcome measures were FPA, peak plantar pressure (PPP), and force-time integral (FTI). A repeated measures ANOVA was conducted to determine group differences in FPA for both walking conditions. Regional differences in PPPs and FTIs between preferred and corrected walking conditions were analyzed using repeated measures ANCOVA. Results: Participants showed a reduction in FPA magnitude on the 'Involved' foot between the preferred and corrected walking conditions ( plessthan 0.01). There were no differences in PPPs or FTIs in any mask between walking conditions (p morethan 0.05). Conclusion: Results from this investigation offer important evidence that people with diabetes can modify their FPA with a simple intervention of visual and verbal cueing. Future research should examine if gait retraining strategies in regular footwear more effectively offload areas of elevated regional plantar stresses and forces in adults with diabetes mellitus and peripheral neuropathy.

Background Although exercise is an effective treatment for fibromyalgia, the relationships between lifestyle physical activity and multiple symptomology domains of fibromyalgia are not clear. Thus, the purpose of this study was to comprehensively examine the relationships between lifestyle physical activity with multiple outcome domains in women with fibromyalgia, including pain, fatigue, function, pain-related psychological constructs, and quality of life. Methods Women (N = 171), aged 20 to 70 years, diagnosed with fibromyalgia, recruited from an ongoing two-site clinical trial were included in this prespecified subgroup analysis of baseline data. Physical activity was assessed using self-report and accelerometry. Symptomology was assessed using questionnaires of perceived physical function, quality of life, fatigue, pain intensity and interference, disease impact, pain catastrophizing, and fear of movement. In addition, quantitative sensory testing of pain sensitivity and performance-based physical function were assessed. Correlation coefficients, regression analyses and between-group differences in symptomology by activity level were assessed, controlling for age and body mass index (BMI). Results Lifestyle physical activity was most closely associated with select measures of physical function and fatigue, regardless of age and BMI. Those who performed the lowest levels of lifestyle physical activity had poorer functional outcomes and greater fatigue than those with higher physical activity participation. No relationships between lifestyle physical activity and pain, pain sensitivity, or pain-related psychological constructs were observed. Conclusions Lifestyle physical activity is not equally related to all aspects of fibromyalgia symptomology. Lifestyle physical activity levels have the strongest correlations with function, physical quality of life, and movement fatigue in women with fibromyalgia. No relationships between lifestyle physical activity and pain, pain sensitivity, or psychological constructs were observed. These data suggest that physical activity levels are more likely to affect function and fatigue, but have negligible relationships with pain and pain-related psychological constructs, in women with fibromyalgia. Trial registration ClinicalTrials.gov, NCT01888640. Registered on 28 June 2013. Electronic supplementary material The online version of this article (10.1186/s13075-018-1671-3) contains supplementary material, which is available to authorized users.

We conducted a systematic review and meta-analysis analysing the existing data on transcutaneous electrical nerve stimulation (TENS) or interferential current (IFC) for chronic low back pain (CLBP) and/or neck pain (CNP) taking into account intensity and timing of stimulation, examining pain, function and disability. Seven electronic databases were searched for TENS or IFC treatment in non-specific CLBP or CNP. Four reviewers independently selected randomized controlled trials (RCTs) of TENS or IFC intervention in adult individuals with non-specific CLBP or CNP. Primary outcomes were for self-reported pain intensity and back-specific disability. Two reviewers performed quality assessment, and two reviewers extracted data using a standardized form. Nine RCTs were selected (eight CLBP; one CNP), and seven studies with complete data sets were included for meta-analysis (655 participants). For CLBP, meta-analysis shows TENS/IFC intervention, independent of time of assessment, was significantly different from placebo/control (p

Aims To determine if participants can reduce foot progression angle (FPA), and if FPA reduction decreases regional plantar stresses and forces in individuals with diabetes. Methods Design Three-group cross-sectional design with repeated measures. subjects twenty-eight participants either with diabetes mellitus (DM), diabetes and peripheral neuropathy with (DMPN+NPU) or without a prior history of ulceration (DMPN−NPU) were studied. Intervention Participants were first instructed to walk over a 3.6 m walkway at their preferred FPA, and then to walk with their foot aligned parallel with the line of gait progression at their self-selected speed. Dynamic plantar kinetics in six masked regions were collected using an EMED-st-P-2 pedobarograph. Main measures Primary outcome measures were FPA, peak plantar pressure (PPP), and force-time integral (FTI). A repeated measures ANOVA was conducted to determine group differences in FPA for both walking conditions. Regional differences in PPPs and FTIs between preferred and corrected walking conditions were analyzed using repeated measures ANCOVA. Results Participants showed a reduction in FPA magnitude on the ‘Involved’ foot between the preferred and corrected walking conditions (p0.05). Conclusion Results from this investigation offer important evidence that people with diabetes can modify their FPA with a simple intervention of visual and verbal cueing. Future research should examine if gait retraining strategies in regular footwear more effectively offload areas of elevated regional plantar stresses and forces in adults with diabetes mellitus and peripheral neuropathy.

Currently, there are no established biomarkers for the diagnosis or symptoms of pain and fatigue in individuals with fibromyalgia (FM). The objective of this study was to identify potential biomarkers in individuals with FM, and to correlate these putative biomarkers with FM-symptoms using a targeted metabolomics approach. The current study was a secondary analysis from baseline data taken in the Fibromyalgia Activity Study with TENS (FAST). We analyzed plasma samples and baseline patient-reported outcomes for resting pain and fatigue from 59 women with FM (mean±SD; age=49.69±11.54, BMI=35.23±10.91) matched with 38 healthy controls (HC) (age=51.0±11.46, BMI=32.33±8.66). Serum/plasma metabolomic extracts were derivatized and analyzed by gas chromatography mass spectrometry for 63 key metabolites representing the tricarboxylic acid cycle, glycolysis, pentose phosphate pathway, amino acid metabolism, neurotransmission, reactive oxygen species defense, and energetics. Differences between FM and HC were assessed for each metabolite using unpaired t-tests (corrected p

Fibromyalgia is a condition characterized by chronic widespread muscle pain and fatigue and associated with significant impairment in perceived function and reduced physical performance. The purpose of this study was to determine the degree to which pain and fatigue are associated with perceived function and physical performance in women with fibromyalgia. Hierarchical linear regression determined the contribution of pain and fatigue (Numeric Rating Scale (NRS) for resting, movement and combined) to perceived function (Fibromyalgia Impact Questionnaire Revised - Function Subscale, FIQR-Function), Multidimensional Assessment of Fatigue - Activities of Daily Living (MAF-ADL) and SF-36 Physical Function Subscale (SF-36-PF) and physical performance (6-Minute Walk Test, 6MWT and Five Time Sit To Stand, 5TSTS) while controlling for age, body mass index, pain catastrophizing, fear of movement, anxiety, and depression in women with fibromyalgia (N = 94). For perceived function, movement pain and movement fatigue together better predicted FIQR-function (adjusted R2 = 0.42, p ≤ 0.001); MAF-ADL (adjusted R2 = 0.41, p ≤ 0.001); and SF-36-PF function (adjusted R2 = 0.34, p ≤ 0.001). For physical performance measures, movement pain and fatigue together predicted 6MWT distance (adjusted R2 = 0.42, p ≤ 0.001) and movement fatigue alone predicted performance time on the 5TSTS (adjusted R2 = 0.20, p ≤ 0.001). Pain and fatigue are significantly associated with and explain more than one-third of the variance in perceived function and physical performance in women with fibromyalgia. NIH Clinicaltrials.gov Registration: NCT01888640 . Registered 13 June 2013.

Purpose: Early ambulation and rehabilitation are recommended for patients undergoing surgical fixation of hip fracture. Gait velocity may be used as an outcome measure for these patients during acute rehabilitation. As an outcome measure, an estimate of meaningful change (responsiveness) in gait velocity for these patients, however, has not been described. The minimum detectable change (MDC) is a value that represents true change in a measure beyond that accounted for by measurement error. The purpose of this study was to quantify MDC in gait velocity as an index of responsiveness for persons in the acute stage of rehabilitation following hip fracture. Methods: The study design was a descriptive cohort study with one repeated measure. A volunteer sample of 16 subjects over the age of 65, at a mean of 4.7 days postsurgical fixation of unilateral hip fracture, participated in the study. The study was conducted in an acute care rehabilitation practice in a large, tertiary care hospital. We measured gait velocity with the 10-meter walk test, estimated test-retest reliability with an intraclass correlation coefficient and quantified responsiveness of gait velocity as the MDC at a 95% level of confidence. Results: Mean gait velocity was 15 cm/s and the test-retest reliability coefficient was equal to 0.823. The MDC in gait velocity during acute rehabilitation following surgical repair for hip fracture was 8.2 cm/s. Conclusions: Self-selected gait velocity in patients during acute rehabilitation following surgical fixation for hip fracture must improve by 8.2 cm/s or more to designate the change as being real change beyond the bounds of measurement error.