Associations of pain sensitivity and conditioned pain modulation with physical activity: findings from the Multicenter Osteoarthritis Study (MOST).

OBJECTIVE: Individuals with chronic pain due to knee osteoarthritis (OA) are insufficiently physically active, and alterations of facilitatory and inhibitory nociceptive signaling are common in this population. Our objective was to examine the association of these alterations in nociceptive signaling with objective accelerometer-based measures of physical activity in a large observational cohort. DESIGN: We used data from the Multicenter Osteoarthritis Study. Measures of peripheral and central pain sensitivity included pressure pain threshold at the knee and mechanical temporal summation at the wrist, respectively. The presence of descending pain inhibition was assessed by conditioned pain modulation (CPM). Physical activity was quantitatively assessed over 7 days using a lower back-worn activity monitor. Summary metrics included steps/day, activity intensity, and sedentary time. Linear regression analyses were used to evaluate the association of pain sensitivity and the presence of descending pain inhibition with physical activity measures. RESULTS: Data from 1873 participants was analyzed (55.9% female, age = 62.8 ± 10.0 years). People having greater peripheral and central sensitivity showed lower step counts. CPM was not significantly related to any of the physical activity measures, and none of the exposures were significantly related to sedentary time. CONCLUSIONS: In this cohort, greater peripheral and central sensitivity were associated with reduced levels of objectively-assessed daily step counts. Further research may investigate ways to modify or treat heightened pain sensitivity as a means to increase physical activity in older adults with knee OA.

Exploring different models of pain phenotypes and their association with pain worsening in people with early knee osteoarthritis: The MOST cohort study.

OBJECTIVE: To determine i) pain phenotypes (PP) in people with early-stage knee osteoarthritis (EKOA); ii) the longitudinal association between the phenotypes and pain worsening at two years. DESIGN: We studied participants with EKOA from the Multicenter Osteoarthritis Study defined as pain intensity ≤3/10, Kellgren and Lawrence grade ≤2, intermittent pain none to sometimes, and no constant pain. Two models of PP were explored. Model A included pressure pain thresholds, temporal summation, conditioned pain modulation, pain catastrophizing, sleep quality, depression, and widespread pain (WSP). In Model B, gait characteristics, quadriceps strength, comorbidities, and magnetic resonance imaging features were added to Model A. Latent Class Analysis was used to create phenotypes, and logistic regression was used to determine their association with pain worsening. RESULTS: 750 individuals (60% females), mean age [standard deviation (SD)]: 60.3 (9.4) were included in Model A and 333 individuals (60% females), mean age (SD): 59.4 (8.1) in Model B. 3-class and 4-class solutions were chosen for Model A and Model B. In Model A, the most "severe" phenotype was dominated by psychosocial factors, WSP, and measures of nervous system sensitization. Similarly in Model B, the Model A phenotype plus gait variables, quadriceps strength, and comorbidities were dominant. Surprisingly, none of the phenotypes in either model had a significant relationship with pain worsening. CONCLUSION: Phenotypes based upon various factors thought to be important for the pain experience were identified in those with EKOA but were not significantly related to pain worsening. These phenotypes require validation with clinically relevant endpoints.

Feasibility of pain informed movement program for people with knee osteoarthritis.

Objective: To establish the feasibility of an intervention consisting of neuromuscular exercise, mind-body techniques, and pain neuroscience education (PNE), referred to as Pain Informed Movement in people with knee Osteoarthritis (KOA). This program has the potential to improve our understanding of intrinsic pain modulation and its role in the management of chronic pain. Methods: This was a single-arm feasibility trial with a nested qualitative component. Primary outcome: complete follow-up. Inclusion criteria: age ≥40 years, KOA clinical diagnosis or meeting KOA NICE criteria, and pain intensity ≥3/10. The program consisted of 8-week in-person and at-home exercise sessions. PNE and mind-body techniques were provided as videos and integrated into the exercise sessions. Participants completed questionnaires and physical assessments including blood draws at baseline and program completion. Secondary feasibility outcomes: acceptability of the intervention, burden, rates of recruitment, compliance and adherence, and adverse events. A priori success criteria were identified. Participants were invited to an online focus group. Results: 19 participants were enrolled, with a complete follow-up rate of 74% (mean age 63.3 years (SD 10.5), 73% female), indicating modifications were necessary to proceed. All other success criteria were met. The focus groups revealed that the video content pertaining to the mind-body techniques would benefit from on screen demonstrations. Conclusion: The Pain Informed Movement program is deemed feasible, with minor modifications needed to proceed. A pilot two-arm RCT will be conducted to establish the feasibility and explore potential effects of Pain Informed Movement compared to conventional neuromuscular exercise and standard OA education.

Pain Informed Movement for people with knee osteoarthritis: Protocol for a pilot randomized controlled trial.

Objective: Conservative pain management strategies for knee osteoarthritis (KOA) have limited effectiveness and do not employ a pain-mechanism informed approach. Pain Informed Movement is a novel intervention combining mind-body techniques with neuromuscular exercise and pain neuroscience education (PNE), aimed at improving endogenous pain modulation. While the feasibility and acceptability of this program has been previously established, it now requires further evaluation in comparison to standard KOA care. Design: This protocol describes the design of a pilot two-arm randomized controlled trial (RCT) with an embedded qualitative component. The primary outcome is complete follow-up rate. With an allocation ratio of 1:1, 66 participants (33/arm) (age ≥40 years, KOA diagnosis or meeting KOA NICE criteria, and pain intensity ≥3/10), will be randomly allocated to two groups that will both receive 8 weeks of twice weekly in-person exercise sessions. Those randomized to Pain Informed Movement will receive PNE and mind-body technique instruction provided initially as videos and integrated into exercise sessions. The control arm will receive neuromuscular exercise and standard OA education. Assessment will include clinical questionnaires, physical and psychophysical tests, and blood draws at baseline and program completion. Secondary outcomes are program acceptability, burden, rate of recruitment, compliance and adherence, and adverse events. Participants will be invited to an online focus group at program completion. Conclusion: The results of this pilot RCT will serve as the basis for a larger multi-site RCT aimed at determining the program's effectiveness with the primary outcome of assessing the mediating effects of descending modulation on changes in pain.

Response to the Letter to the Editor-in-Chief.

Author response to the JOSPT Letter to the Editor-in-Chief "A Second Look at the Risks of Serious Adverse Events with Orthopaedic Manual Therapy, Paracetamol, and NSAID Treatment of Neck Pain" J Orthop Sports Phys Ther 2023;53(6):1-2. doi:10.2519/jospt.2023.0202-R.

Identifying chronic low back pain phenotypic domains and characteristics accounting for individual variation: a systematic review.

ABSTRACT: Interpatient variability is frequently observed among individuals with chronic low back pain (cLBP). This review aimed at identifying phenotypic domains and characteristics that account for interpatient variability in cLBP. We searched MEDLINE ALL (through Ovid), Embase Classic and EMBASE (through Ovid), Scopus, and CINAHL Complete (through EBSCOhost) databases. Studies that aimed to identify or predict cLBP different phenotypes were included. We excluded studies that focused on specific treatments. The methodological quality was assessed using an adaptation of the Downs and Black tool. Forty-three studies were included. Although the patient and pain-related characteristics used to identify phenotypes varied considerably across studies, the following were among the most identified phenotypic domains and characteristics that account for interpatient variability in cLBP: pain-related characteristics (including location, severity, qualities, and duration) and pain impact (including disability, sleep, and fatigue), psychological domains (including anxiety and depression), behavioral domains (including coping, somatization, fear avoidance, and catastrophizing), social domains (including employment and social support), and sensory profiling (including pain sensitivity and sensitization). Despite these findings, our review showed that the evidence on pain phenotyping still requires further investigation. The assessment of the methodological quality revealed several limitations. We recommend adopting a standard methodology to enhance the generalizability of the results and the implementation of a comprehensive and feasible assessment framework to facilitate personalized treatments in clinical settings.

Feasibility, Usability, and Acceptability of Online Mind-Body Exercise Programs for Older Adults: A Scoping Review.

Objectives: Engaging in mind-body exercises (MBEs: e.g., Tai Chi and yoga) can have physical and mental health benefits particularly for older adults. Many MBEs require precise timing and coordination of complex body postures posing challenges for online instruction. Such challenges include difficulty viewing instructors as they demonstrate different movements and lack of feedback to participants. With the shift of exercise programs to online platforms during the COVID-19 pandemic, we conducted a scoping review to examine the feasibility, usability, and acceptability of online MBE classes for older adults. Materials and Methods: We followed the scoping review methodology and adhered to the PRISMA reporting checklist. We searched five databases: Medline, Embase, CINHAL, Web of Science, and ACM digital library. Screening of articles and data extraction was conducted independently by two reviewers. Settings/Location: Online/virtual. Subjects: Older adults ≥55 years of age. Outcome Measures: Feasibility measures. Results: Of 6711 studies retrieved, 18 studies were included (715 participants, mean age 66.9 years). Studies reported moderate to high retention and adherence rates (mean >75%). Older adults reported online MBE classes were easy to use and reported high satisfaction with the online format. We also identified barriers (e.g., lack of space and privacy and unstable internet connection) and facilitators (e.g., convenience and technical support) to the online format. Opinions related to social connectedness were mixed. Conclusion: Online MBE programs for older adults appear to be a feasible and acceptable alternative to in-person programs. It is important to consider the type of exercise (e.g., MBE), diverse teaching styles, and learner needs when designing online exercise classes.

Assessing cultural competency among Canadian chiropractors: a cross-sectional survey of Canadian Chiropractic Association members.

BACKGROUND: There is a paucity of research assessing cultural competency among Canadian chiropractors. Therefore, the aims of this study were to (1) measure cultural competency among Canadian chiropractors, (2) understand chiropractors' perspectives of challenges and attitudes regarding the delivery of chiropractic services to equity-seeking communities, and (3) assess contextual factors associated with cultural competency. METHODS: We conducted a cross-sectional survey of members of the Canadian Chiropractic Association (CCA) (May-July 2021). The survey instrument consisted of 57 questions related to demographics, cultural competency, perceptions about health disparities, and challenges in delivery of rehabilitation. Cultural competency was measured using the Cultural Awareness and Sensitivity and Cultural Competence Behaviours subscales of the Cultural Competence Assessment Instrument. We conducted a multivariate linear regression to assess factors that may be associated with cultural competency. RESULTS: A total of 3143 CCA members responded (response rate of 41%). Mean scores for the Cultural Awareness and Sensitivity subscale were 5.8/7 (95% CI 5.7; 5.8) and 4.2/7 (95% CI 4.1; 4.2) for the Cultural Competence Behaviour subscale. Most chiropractors (72-78%) reported observing important cultural health disparities across various care-related outcomes. Cost of services and language were identified as barriers to providing care to equity-seeking communities. Cultural Awareness and Sensitivity scores were weakly associated with gender (men), years of clinical practice, cultural health disparities, the statement "I think some people have an agenda to look for discrimination even where it does not exist (DEI attitudes)," race (Caucasian), and prior DEI training, (R2 = 0.15, p < 0.0001). Cultural Competence Behaviour scores were weakly associated with race (Caucasian), cultural health disparities, prior DEI training, increased years of clinical experience, and higher Cultural Awareness and Sensitivity scores (R2 = 0.19, p < 0.0001). CONCLUSION: This study provides the first description of cultural competency within the chiropractic profession in Canada. Findings suggest a gap between knowledge and behaviour and uncover several barriers and challenges that may inform the development of profession-specific training in cultural competence.

Assessing Validity of the Original and Rasch Versions of the Central Sensitization Inventory with Psychophysical Tests in People with Knee Osteoarthritis.

OBJECTIVE: To determine the extent of agreement between the original Central Sensitization Inventory (CSI) and the Rasch-calibrated version (RC-CSI) and to explore the association of both versions with psychophysical tests and their respective sensitivity and specificity. METHODS: Patients with knee osteoarthritis who were enrolled in a multicenter cohort study in Montreal, Canada, completed the original CSI, the RC-CSI, and psychophysical tests (i.e., pressure pain thresholds, temporal summation, conditioned pain modulation) according to standardized protocols. Bland-Altman analyses assessed the agreement between the original CSI and the RC-CSI; Spearman correlations and chi-squared analyses evaluated the association between the two CSI scores and the psychophysical tests. A CSI cut point of 40 and an RC-CSI cut point of 31.37 were used. Receiver operating characteristic curves and the resulting sensitivity and specificity with psychophysical tests were also analyzed. RESULTS: Two hundred ninety-three participants were included (58.7% female, mean age of 63.6 years, and body mass index 31.9 kg/m2). The original CSI and RC-CSI mean difference, 3.3/8.2, t(292) = 8.84 (P < 0.001), was significantly different and indicated a small bias. Small but significant inverse correlations were found for the original CSI and RC-CSI scores with pressure pain thresholds at the forearm and patella, with variance explained ranging from 0.01 to 0.12. The largest area under the curve suggested cut points of 23 (CSI) and 25 (RC-CSI) with 80.9% sensitivity and 38.5% specificity. CONCLUSIONS: Because of poor variance explained with psychophysical tests and high false positive rates, our results indicate that there is little clinical value of using either version of the CSI in people with knee osteoarthritis.

International Framework for Examination of the Cervical Region for Potential of Vascular Pathologies of the Neck Prior to Musculoskeletal Intervention: International IFOMPT Cervical Framework.

SYNOPSIS: This position statement, stemming from the International IFOMPT (International Federation of Orthopaedic Manipulative Physical Therapists) Cervical Framework, was developed based upon the best contemporary evidence and expert opinion to assist clinicians during their clinical reasoning process when considering presentations involving the head and neck. Developed through rigorous consensus methods, the International IFOMPT Cervical Framework guides assessment of the cervical spine region for potential vascular pathologies of the neck in advance of planned interventions. Within the cervical spine, events and presentations of vascular pathologies of the neck are rare but are an important consideration as part of patient examination. Vascular pathologies may be recognizable if the appropriate questions are asked during the patient history-taking process, if interpretation of elicited data enables recognition of this potential, and if the physical examination can be adapted to explore any potential vasculogenic hypothesis. J Orthop Sports Phys Ther 2023;53(1):7-22. Epub: 14 September 2022. doi:10.2519/jospt.2022.11147.

Undertaking Rehabilitation Research During the COVID-19 Pandemic: Emergent Strategies From a Trainee-Faculty Workshop.

Background: The COVID-19 pandemic has disrupted everyday rehabilitation research. Many academic institutions have halted in-person human research including rehabilitation sciences. Researchers are faced with several barriers to continuing their research programs. The purpose of this perspective article is to report the results of an interdisciplinary workshop aimed at understanding the challenges and corresponding strategies for conducting rehabilitation research during the COVID-19 pandemic. Methods: Twenty-five rehabilitation researchers (17 trainees and eight faculty) attended a 2-h facilitated online workshop in to discuss challenges and strategies they had experienced and employed to conduct rehabilitation research during the COVID-19 pandemic. Results: Rehabilitation researchers reported challenges with (1) pandemic protocol adjustments, (2) participant accessibility, and (3) knowledge dissemination, along with corresponding strategies to these challenges. Researchers experienced disruptions in study outcomes and intervention protocols to adhere to public health guidelines and have suggested implementing novel virtual approaches and study toolkits to facilitate offsite assessment. Participant accessibility could be improved by engaging community stakeholders in protocol revisions to ensure equity, safety, and feasibility. Researchers also experienced barriers to virtual conferences and publication, suggested opportunities for smaller networking events, and revisiting timeframes for knowledge dissemination. Conclusion: This perspective article served as a catalyst for discussion among rehabilitation researchers to identify novel and creative approaches that address the complexities of conducting rehabilitation research during the COVID-19 pandemic and beyond.

Validity of the Central Sensitization Inventory (CSI) through Rasch analysis in patients with knee osteoarthritis.

INTRODUCTION/OBJECTIVE: Central sensitization (CS) is a known contributor to chronic pain in people with knee osteoarthritis (KOA) and is commonly measured by psychophysical testing or patient-reported methods such as the Central Sensitization Inventory (CSI). However, previous studies have shown a weak association between the two. We therefore sought to evaluate the validity of the CSI through Rasch analysis in patients with KOA. METHOD: We performed a secondary analysis of a multicenter cohort study with patients with KOA consulting orthopedic surgeons. Rasch analysis was conducted considering person factors of age, sex, BMI, pain intensity, pain catastrophizing, and quantitative sensory test findings using pressure pain thresholds and temporal summation to assess how the CSI fits to the Rasch model (supporting validity). We used RUMM2030 software to model fit estimates, making adjustments as required to achieve model fit (P > 0.05). RESULTS: Data from 293 patients were included (58.7% female, mean age 63.6 years, 49.1% obese) Initial evaluation with Rasch modelling indicated misfit. Eleven of 25 items on the CSI displayed disordered thresholds which were rescored by collapsing response categories until the thresholds demonstrated sequential progression. Reanalysis demonstrated persistent model misfit so a subtest was developed to address local dependency of 6 items. Thereafter, model fit was achieved (P = 0.071, indicating not differing from Rasch model) and acceptable unidimensionality (P = 0.068 with 95% CI 0.043-0.093). CONCLUSIONS: The CSI was able to be fit to the Rasch model after rescoring while retaining all 25 items. The unidimensionality validates CS as measured by the CSI as a singular construct. Key Points • The Central Sensitization Inventory (CSI) was able to be fit to the Rasch model after rescoring while retaining all 25 items. • The unidimensionality of the CSI validates CS as a singular construct. • Our results suggest rescoring of the CSI for people with KOA, but it should be confirmed and replicated in larger samples prior to clinical use.

Management of Chronic Musculoskeletal Pain Through a Biopsychosocial Lens.

Chronic musculoskeletal pain continues to constitute a rising cost and burden on individuals and society on a global level, thus driving the demand for improved management strategies. The biopsychosocial model has long been a recommended approach to help manage chronic pain, with its consideration of the person and his or her experiences, psychosocial context, and societal considerations. However, the biomedical model continues to be the basis of athletic therapy and athletic training programs and therefore clinical practice. For more than 30 years, psychosocial factors have been identified in the literature as outcome predictors relating to chronic pain, including (but not limited to) catastrophizing, fear avoidance, and self-efficacy. Physical assessment strategies such as validated outcome measures can be used by the athletic therapist and athletic trainer to determine the presence or severity (or both) of nonbiogenic pain. Knowledge of these predictors and strategies allows the athletic therapist and athletic trainer to frame the use of exercise (eg, graded exposure), manual therapy, and therapeutic modalities in the appropriate way to improve clinical outcomes. Through changes in educational curricula content, such as those recommended by the International Association for the Study of Pain, athletic therapists and athletic trainers can develop profession-specific knowledge and skills that will enhance their clinical practice and enable them to better assist those living with chronic musculoskeletal pain conditions.

Use of IMMPACT Recommendations to Explore Pain Phenotypes in People with Knee Osteoarthritis.

OBJECTIVE: Knee osteoarthritis (OA) is a disease of multiple phenotypes of which a chronic pain phenotype (PP) is known. Previous PP studies have focused on one domain of pain and included heterogenous variables. We sought to identify multidimensional PPs using the IMMPACT recommendations and their relationship to clinical outcomes. METHODS: Participants >40 years of age with knee OA having a first-time orthopedic consultation at five university affiliated hospitals in Montreal, Quebec, and Hamilton (Canada) were recruited. Latent profile analysis was used to determine PPs (classes) using variables recommended by IMMPACT. This included pain variability, intensity and qualities, somatization, anxiodepressive symptoms, sleep, fatigue, pain catastrophizing, neuropathic pain, and quantitative sensory tests. We used MANOVA and χ2 tests to assess differences in participant characteristics across the classes and linear and Poisson regression to evaluate the association of classes to outcomes of physical performance tests, self-reported function and provincial healthcare data. RESULTS: In total, 343 participants were included (mean age 64 years, 64% female). Three classes were identified with increasing pain burden (class3 > class1), characterized by significant differences across most self-report measures and temporal summation, and differed in terms of female sex, younger age, lower optimism and pain self-efficacy. Participants in class2 and class3 had significantly worse self-reported function, stair climb and 40 m walk tests, and higher rates of healthcare usage compared to those in class1. CONCLUSIONS: Three distinct PPs guided by IMMPACT recommendations were identified, predominated by self-report measures and temporal summation. Using this standardized approach may improve PP study variability and comparison.

Development of a national pain management competency profile to guide entry-level physiotherapy education in Canada.

BACKGROUND: National strategies from North America call for substantive improvements in entry-level pain management education to help reduce the burden of chronic pain. Past work has generated a valuable set of interprofessional pain management competencies to guide the education of future health professionals. However, there has been very limited work that has explored the development of such competencies for individual professions in different regions. Developing profession-specific competencies tailored to the local context is a necessary first step to integrate them within local regulatory systems. Our group is working toward this goal within the context of entry-level physiotherapy (PT) programs across Canada. AIMS: This study aimed to create a consensus-based competency profile for pain management, specific to the Canadian PT context. METHODS: A modified Delphi design was used to achieve consensus across Canadian university-based and clinical pain educators. RESULTS: Representatives from 14 entry-level PT programs (93% of Canadian programs) and six clinical educators were recruited. After two rounds, a total of 15 competencies reached the predetermined endorsement threshold (75%). Most participants (85%) reported being "very satisfied" with the process. CONCLUSIONS: This process achieved consensus on a novel pain management competency profile specific to the Canadian PT context. The resulting profile delineates the necessary abilities required by physiotherapists to manage pain upon entry to practice. Participants were very satisfied with the process. This study also contributes to the emerging literature on integrated research in pain management by profiling research methodology that can be used to inform related work in other health professions and regions.

Contexte: Contexte: Les stratégies nationales nord-américaines préconisent des améliorations sensibles à la formation de base en matiére de prise en charge de la douleur afin de contribuer à la réduction du fardeau de la douleur chronique. Des travaux antérieurs ont généré un ensemble de compétences interprofessionnelles utile en matiére de prise en charge de la douleur afin de guider la formation des futurs professionnels de la santé. Cependant, trés peu de travaux ont porté sur l'acquisition de telles compétences pour des professions individuelles dans différentes régions. L'uisition de compétences spécifiques à une profession adaptées au contexte local est une première étape nécessaire pour leur intégration dans les systèmes réglementaires locaux. Notre groupe travaille à cet objectif dans le cadre de programmes de formation de base en physiothèrapie partout au Canada.Objectifs: Cette étude visait à créer un profil de compétences consensuel pour la prise en charge de la douleur, propre au contexte canadien de la physiothérapie.Méthodes: Un devis Delphi modifié a étè utilisé pour parvenir à un consensus parmi des formateurs en milieu universitaire et clinique en matière de douleur en milieu universitaire et clinique.Résultats: Des représentants de 14 programmes de formation de base en physiothérapie (93 % des programmes canadiens) et de six formateurs en milieu clinique ont été recrutés. Après deux tours, 15 compétences ont atteint le seuil d'approbation prédéterminé (75 %). La plupart des participants (85 %) ont déclaré être « très satisfaits ¼du processus.Conclusions: Ce processus a permis de dégager un consensus sur un nouveau profil de compétences en matiére de prise en charge de la douleur propre au contexte canadien de la physiothérapie. Ce profil délimite les habiletés requises des physiothérapeutes pour prendre en charge la douleur en début de pratique. Les participants ont été très satisfaits du processus. Cette étude contribue également à la littérature émergente sur la recherche intégrée en matière de prise en charge de la douleur en définissant une méthodologie de recherche qui peut être utilisée pour éclairer des travaux similaires dans d'autres professions de la santé et dans d'autres régions.

Factors Associated with Intermittent, Constant, and Mixed Pain in People with Knee Osteoarthritis.

Purpose: To explore factors associated with intermittent, constant, and mixed pain in people with knee osteoarthritis. Method: We conducted a secondary analysis of a cross-sectional multicentre study with adults ≥ 40 years with knee osteoarthritis. Participants completed questionnaires on personal (e.g., demographics, comorbidities), physical (e.g., physical function), psychological (e.g., depressive symptoms), pain (e.g., qualities), and tests for physical performance and nervous system sensitivity. We qualified patients' pain as intermittent, constant, or mixed using the Modified painDETECT Questionnaire and assessed associations with the variables using multinomial logistic regression. Results: The 279 participants had an average age of 63.8 years (SD 9.6), BMI of 31.5 kg/m2 (SD 8.7), and 58.6% were female. Older age (odds ratio [OR] 0.95; 95% CI: 0.90, 1.00) and higher self-reported physical function (OR 0.94; 95% CI: 0.91, 0.98) were associated with a lower likelihood of mixed pain compared with intermittent pain. Higher pain intensity (OR 1.25; 95% CI: 1.07, 1.47) was related to a 25% higher likelihood of mixed pain compared with intermittent pain. Conclusions: This study provides initial data for associations of personal, pain, and physical function factors with different pain patterns. Awareness of these factors can help clinicians develop targeted strategies for managing patients' pain.

Objectif : explorer les facteurs associés à la douleur intermittente, constante et mixte chez les personnes atteintes d'arthrose du genou. Méthodologie : analyse secondaire d'une étude multicentrique transversale auprès d'adultes atteints d'arthrose du genou de 40 ans et plus. Les participants ont repris des questionnaires sur les aspects personnels (démographie, comorbidité), physiques (fonctionnement physique) et psychologiques (symptômes dépressifs) et sur la douleur (propriétés) et ils ont effectué des tests de performance physique et de sensibilité du système nerveux. Les chercheurs ont qualifié la douleur des patients d'intermittente, de constante ou de mixte, utilisé le questionnaire painDETECT modifié et évalué les associations avec les variables de régression logistique multinomiale. Résultats : les 279 participants avaient un âge moyen de 63,8 ans (ÉT 9,6), un indice de masse corporelle de 31,5 kg/m2 (ÉT 8,7), et 58,6 % étaient des femmes. Un âge plus avancé (rapport de cotes [RC] 0,95; IC à 95 % : 0,90, 1,00) et un fonctionnement physique autodéclaré plus élevé (RC 0,94; IC à 95 % : 0,91, 0,98) étaient liés à une plus faible probabilité de douleur mixte que de douleur intermittente. Une intensité de douleur plus marquée (RC 1,25; IC à 95 % : 1,07, 1,47) était liée à une probabilité 25 % fois plus élevée de douleur mixte que de douleur intermittente. Conclusions : la présente étude fournit des données initiales pour associer les facteurs personnels, les facteurs liés à la douleur et ceux liés au fonctionnement physique à divers profils de douleur. S'ils connaissent ces facteurs, les cliniciens seront mieux en mesure de préparer des stratégies ciblées pour prendre en charge la douleur du patient.

Association of Pain Sensitization and Conditioned Pain Modulation to Pain Patterns in Knee Osteoarthritis.

OBJECTIVE: To examine the cross-sectional association of ascending pain mechanisms, implicated in pain sensitization, and descending pain modulation with pain patterns and unpredictability of pain. METHODS: The Multicenter Osteoarthritis Study is a longitudinal cohort of older adults with or at risk of knee osteoarthritis. Peripheral and central ascending pain mechanisms were assessed using quantitative sensory tests, pressure pain thresholds using a handheld pressure algometer (knee/peripheral and wrist/central), and temporal summation using weighted probes (wrist/central). Descending modulation was assessed by conditioned pain modulation using pressure pain thresholds and a forearm ischemia test. Pain patterns were characterized based on responses to the Intermittent and Constant Osteoarthritis Pain questionnaire: 1) no intermittent or constant pain, 2) intermittent pain only, 3) constant pain only, and 4) combined constant and intermittent pain. A question regarding frequency assessed unpredictable pain. We assessed the association of quantitative sensory test measures to pain patterns using regression models with generalized estimating equations. RESULTS: There were 2,794 participants (mean age 63.9 years, body mass index 29.5 kg/m2 , and 57% female). Lower pain sensitization by wrist pressure pain threshold (odds ratio [OR] 0.80 [95% confidence interval (95% CI) 0.68, 0.93]) and adequate conditioned pain modulation (OR 1.45 [95% CI 1.10, 1.92]) were associated with having constant ± intermittent pain compared with intermittent pain only. Higher pain sensitization (by pressure pain thresholds and temporal summation) was associated with a higher likelihood of unpredictable pain. CONCLUSION: Knee pain patterns appear to be related to peripheral ± central facilitated ascending pain mechanisms and descending modulatory mechanisms. These findings highlight the need for a broader approach to understanding pain mechanisms by symptomatic disease progression.

Health-Related Outcomes 3-15 Years Following Ankle Sprain Injury in Youth Sport: What Does the Future Hold?

BACKGROUND: This study examined the association between youth sport-related ankle sprain injury and health-related outcomes, 3-15 years postinjury. METHODS: A historical cohort study in which uninjured controls were cluster-matched with injured cases. The primary outcome was self-reported Foot and Ankle Outcome Score (FAOS). Secondary outcomes included measures of adiposity, validated questionnaires for physical activity, athletic identity, fear of pain, and tests of strength, balance, and function. RESULTS: We recruited 86 participants (median age of 23 years; 77% female); 50 with a time-loss ankle sprain, median of 8 years postinjury, and 36 uninjured controls cluster-matched by sex and sport. Based on mixed effects multivariable regression models, previously injured participants demonstrated poorer outcomes than controls on all 5 FAOS subscales regardless of sex and time since injury, with the largest differences observed in symptoms (-20.9, 99% CI: -29.5 to -12.3) and ankle-related quality of life (-25.3, 99% CI: -34.7 to -15.9) subscales. Injured participants also had poorer unipedal dynamic balance (-1.9, 99% CI: 3.5 to -0.2) and greater fear of pain (7.2, 99% CI: 0.9-13.4) compared with controls. No statistically significant differences were found for other secondary outcomes. CONCLUSION: At 3-15 years following time-loss ankle sprain injury in youth sport, previously injured participants had more pain and symptoms, poorer self-reported function, ankle-related quality of life, reduced sport participation, balance, and greater fear of pain than controls. This underlines the need to promote the primary prevention of ankle sprains and secondary prevention of potential health consequences, including posttraumatic osteoarthritis. LEVEL OF EVIDENCE: Level III, historical cohort study.