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.

Task-based measures of sensitivity to physical activity predict daily life pain and mood among people living with back pain.

BACKGROUND: Clinical interventions aim to improve the daily life experiences of patients. However, past research has highlighted important discrepancies between commonly used assessments (e.g. retrospective questionnaires) and patients' daily life experiences of pain. These gaps may contribute to flawed clinical decision-making and ineffective care. Recent work suggests that real-time, task-based clinical assessments may help reduce these discrepancies by adding predictive value in explaining daily life pain experiences. This study aimed to investigate these relationships by evaluating whether task-based measures of sensitivity to physical activity (SPA) predict daily life pain and mood, beyond traditional pain-related questionnaires. METHODS: Adults with back pain (<6-month onset) answered pain-related questionnaires and completed a standardized lifting task. SPA-Pain, SPA-Sensory and SPA-Mood were, respectively, assessed as task-evoked changes in pain intensity, pressure pain threshold (back, hands), situational catastrophizing. Over the next 9 days, daily life pain and mood were assessed using smartphone-based ecological momentary assessment (EMA-Pain and EMA-Mood, respectively) with stratified random sampling. Data analyses estimated fixed effects (b) using multilevel linear modelling with random intercepts. RESULTS: Median EMA completion per participant was 66.67% (n = 67 participants). After controlling for covariates, SPA-Pain was associated with EMA-Pain (b = 0.235, p = 0.002) and SPA-Psych approached significance with EMA-Mood (b = -0.159, p = 0.052). CONCLUSIONS: Task-based assessment of SPA helps explain daily life pain and mood among adults with back pain, beyond traditional questionnaires. Adding task-based assessment of SPA may achieve a more complete picture of pain and mood in daily life, offering clinicians better guidance when prescribing activity-based interventions that are designed to modify daily life behaviour, such as graded activity. SIGNIFICANCE: This study found that, among people with back pain, task-based measures of sensitivity to physical activity contribute additional predictive value for daily life pain and mood beyond self-report questionnaires. Findings suggest that real-time, task-based measures may help mitigate some of the shortcomings that are commonly associated with retrospective questionnaires.

International consensus on the non-pharmacological and non-surgical management of osteoporotic vertebral fractures.

We identified a knowledge gap in the non-pharmacological and non-surgical management of osteoporotic vertebral fractures. MAIN RESULTS: This international consensus process established multidisciplinary biopsychosocial recommendations on pain, nutrition, safe movement, and exercise for individuals with acute and chronic vertebral fractures. SIGNIFICANCE: These recommendations will guide clinical practice and inform interventions for future research. PURPOSE: To establish international consensus on recommendations for the non-pharmacological and non-surgical management of osteoporotic vertebral fractures. METHODS: We adopted a five-step modified Delphi consensus process: (1) literature search and content analysis, (2) creation of the survey, (3) selection of the expert panel, (4) first round of the rating process, and (5) second round of the rating process. The first round included 49 statements and eight open-ended questions; the second round included 30 statements. Panelists were asked to rate their agreement with each of the statements using a 9-point scale, with the option to provide further comments. Consensus for each statement was determined by counting the number of panelists whose rating was outside the 3-point region containing the median. RESULTS: We invited 76 people with degree in medicine, physiotherapy, kinesiology, and experience in the management of osteoporotic vertebral; 31 (41%) and 27 (36%) experts agreed to participate to the first and the second round, respectively. The mean percentage agreement after the first and second rounds was 76.6% ± 16.0% and 90.7% ± 6.5%, respectively. We established consensus on recommendations on pain, early satiety, weight loss, bracing, safe movement, and exercise for individuals with acute and chronic vertebral fractures. CONCLUSION: Our international consensus provides multidisciplinary biopsychosocial recommendations to guide the management of osteoporotic vertebral fractures and inform interventions for future research.