9 randomized controlled trials (n= 696 patients) of low to moderate quality were included in this systematic review and meta-analysis to determine the effects of isokinetic muscle strengthening on pain, function, and disability in patients with knee osteoarthritis when compared to another isokinetic muscle strengthening treatment, another muscle reinforcement treatment, or no treatment. Data of the following outcomes were available for meta-analysis: standing pain, Lequesne index for function, WOMAC index, and ambulation speed. Findings indicated significant effects favouring isokinetic muscle strengthening for reduced pain and disability outcomes, but a nonsignificant effect was found for walking speed.