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.