Objective: To determine to what extent articular, kinesiological, and psychological factors each contribute to pain and disability in patients with osteoarthritis (OA), after controlling for other factors.
Methods: Cross sectional study among 200 patients with OA of the hip or knee. Dependent variables include pain (visual analog scale), self-reported disability (questionnaire), and observed disability (performance of standardized tasks). Independent variables include joint degeneration (radiographs), muscle strength (dynamometer), range of joint motion (goniometer), pain coping (behavioral and cognitive strategies), and psychological well being (depression, anxiety, cheerfulness). Multiple regression analysis was used.
Results: Pain was found to be associated with muscle weakness and pain coping (p < 0.05). Disability was associated with muscle weakness, range of joint motion, pain, pain coping, and psychological well being (all p < 0.05). Both pain and disability were most strongly associated with kinesiological characteristics and pain coping.
Conclusion: After controlling for the other characteristics, kinesiological and psychological characteristics in patients with OA are each associated with disability. The association with pain is less clear. Future research on mechanisms underlying these associations is warranted.