Is walking for exercise beneficial for people with knee osteoarthritis?

Does walking for exercise have a beneficial long-term effect in patients with knee osteoarthritis (OA)? In a study, researchers used data from the Osteoarthritis Initiative — a U.S. community-based, prospective cohort study — to address this question in 1,200 participants (mean age, 63) with radiographic evidence of knee OA.

About three quarters of participants reported walking for exercise somewhat regularly since age 50. During 4 years of follow-up, walkers were less likely than nonwalkers to report new frequent knee pain; however, among participants who already had frequent knee pain, walking was not associated with improved symptoms during follow-up. Walking also was associated with slightly less likelihood of OA progression on serial radiographs, but the statistical significance of this finding was borderline. These analyses were adjusted for age, sex, and radiographic extent of OA.

Based on these findings, we could reasonably advise people with knee OA and infrequent or non-severe pain that walking for exercise might prevent or delay progression of symptoms. Because a long-term randomised trial of walking for exercise (vs. no walking) is unlikely to happen, observational studies will have to suffice. Reverse causality is a potential problem in a study like this (i.e., more advanced OA can deter people from walking), but the researchers took some analytic steps to minimise this effect.

Source: Arthritis Rheumatol 2022 Oct; 74:1660