DISCUSSION
Both aerobic walking and home based quadriceps strengthening
exercises are effective at reducing pain and disability in
subjects with knee osteoarthritis. No advantage of one form
of exercise over the other was found on indirect comparison
of pooled data. That both interventions are effective has
implications for clinical practice. Adherence is a major
predictor of response to exercise, and offering patients the
choice between two effective interventions has the potential
to improve adherence and hence outcome. To make a full
comparison of the relative efficacy of aerobic walking and
quadriceps strengthening exercise requires an adequately
powered RCT, and a factorial design would allow the
interaction between both forms of exercise to be investigated.