The aim of this study was to determine the effect of a structured RT intervention on overall levels of moderate- and vigorous-intensity physical activity (MVPA) in patients with early-onset knee OA. The study compared patients with early-onset OA who participated in an RT program, those who participated in a self-management (SM) program, and those who participated in both RT and SM. Because participants randomly assigned to receive the RT intervention may simply switch activity modes, resulting in little net effect, we assessed total MVPA in addition to tracking changes in strength (force-generating capacity). The participants in this study were 171 patients with knee OA. They had a mean age of 55.1 years, a mean body mass index of 27.6 kg/m(2), and radiographic status of grade II OA in at least one knee, as defined by the Kellgren and Lawrence classification. They wore an accelerometer while awake at baseline and at 3 and 9 months of intervention.Â The participants engaged in MVPA a mean of 26.2 minutes per day at baseline. Both groups significantly increased their MVPA from baseline to 3 months; SM group by 22%, but only the RT group sustained those changes at 9 months. A significant group x time interaction for MVPA indicated that the RT group maintained higher MVPA levels than the SM group.
Patients with early-onset OA of the knee can engage in an RT program without sacrificing their overall MVPA levels. These results support the value of RT for management of knee OA.
Farr JN, Going SB, McKnight PE, Kasle S, Cussler EC, Cornett M. Progressive resistance training improves overall physical activity levels in patients with early osteoarthritis of the knee: a randomized controlled trial. Phys Ther. 2010 Mar;90(3):356-66