Effects of Elastic Resistance Exercise After Total Knee Replacement on Muscle Mass and Physical Function in Elderly Women With Osteoarthritis: A Randomized Controlled Trial

OBJECTIVE Knee osteoarthritis and age are associated with high sarcopenia risk, especially in patients who have received total knee replacement. The aim of this study was to identify the effects of elastic resistance exercise training after total knee replacement on muscle mass and physical outcomes in older women with knee osteoarthritis. DESIGN Sixty older women who received unilateral primary total knee replacement surgery were randomized to an experimental group, which received 12 wks of postoperative elastic resistance exercise training, or a control group, which received standard care. The outcome measures included physical function performance (ie, Timed Up & Go, gait speed, forward reach, single-leg stance, timed chair rise), appendicular lean mass, and the Western Ontario and McMaster Universities Osteoarthritis Index. The assessment time points were 2 wks before surgery (T0), 1 mo after surgery (T1, before resistance exercise training), and 4 mos after surgery (T2, upon completion of resistance exercise training). RESULTS After 12 wks of postoperative elastic resistance exercise training, the experimental group exhibited a significantly greater change in appendicular lean mass (mean difference = 0.81 kg, P = 0.004) than the control group. Elastic resistance exercise training also exerted significant effects on Timed Up & Go and gait speed with mean differences of 0.28 m/sec (P < 0.001) and -2.66 secs (P < 0.001), respectively. CONCLUSIONS A 12-wk elastic resistance exercise training program after total knee replacement exerted benefits on muscle mass, mobility, and Western Ontario and McMaster Universities Osteoarthritis Index functional outcomes in older women with knee osteoarthritis.