To test the effects of a high intensity home-based progressive strength training program on the clinical signs and symptoms of osteoarthritis (OA) of the knee.
Forty-six community dwelling patients, aged 55 years or older with knee pain and radiographic evidence of knee OA, were randomized to a 4 month home based progressive strength training program or a nutrition education program (attention control). Thirty-eight patients completed the trial with an adherence of 84% to the intervention and 65% to the attention control. The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index pain and physical function subscales. Secondary outcomes included clinical knee examination, muscle strength, physical performance measures, and questionnaires to measure quality of life variables.
Patients in the strength training group who completed the trial had a 71% improvement in knee extension strength in the leg reported as most painful versus a 3% improvement in the control group (p < 0.01). In a modified intent to treat analysis, self-reported pain improved by 36% and physical function by 38% in the strength training group versus 11 and 21%, respectively, in the control group (p = 0.01 for between group comparison). In addition, those patients in the strength training group who completed the trial had a 43% mean reduction in pain (p = 0.01 vs controls), a 44% mean improvement in self-reported physical function (p < 0.01 vs controls), and improvements in physical performance, quality of life, and self-efficacy when compared to the control group.
High intensity, home based strength training can produce substantial improvements in strength, pain, physical function and quality of life in patients with knee OA.