"Exercise for lower limb osteoarthritis: systematic review incorporating trial sequential analysis and network meta-analysis"
BMJ Sep 20
http://www.bmj.com/content/347/bmj.f5555
"Conclusions As of 2002 sufficient evidence had accumulated to show significant benefit of exercise over no exercise in patients with osteoarthritis, and further trials are unlikely to overturn this result. An approach combining exercises to increase strength, flexibility, and aerobic capacity is likely to be most effective in the management of lower limb osteoarthritis. The evidence is largely from trials in patients with knee osteoarthritis."