Dynamic weight-bearing assessment of pain in knee osteoarthritis: construct validity, responsiveness, and interpretability in a research setting.

The DAP possesses divergent validity compared to other instruments for knee OA, supporting the potential for this new way of assessing pain directly during activity. Importantly, the DAP change-scores correspond to patient-reported changes in pain, showing responsiveness. A change of 2.4 or more can be interpreted as clinically relevant. The DAP is a promising alternative to using 'pain on walking' as a clinical trial inclusion criterion/outcome.