[Non-pharmacological, non-technical treatments for musculoskeletal disease: methodological challenges of clinical trials using the example of knee osteoarthritis and falls in the elderly].

Physical therapy modalities are regarded as an integral part of the treatment of musculoskeletal diseases like osteoarthritis of the knee or falls in the elderly. Guidelines and treatment recommendations promote such interventions. However, the evidence supporting physical therapy modalities is often weaker than that found for drug treatments. One reason is that a simple blinding of treatment assignments by means of a placebo is usually not possible. Another issue is patient preferences that have an impact on the conduct of the study and the interpretation of the results. This article highlights methodological challenges of studies investigating physical therapy modalities, and points out some possible solutions. (As supplied by publisher).