Why Is Exercise Effective in Reducing Pain in People with Osteoarthritis?

Abstract

The aim of this narrative review was to summarize the beneficial effects of exercise for those with symptomatic hip and knee osteoarthritis (OA) utilizing data along the pipeline from translational to clinical studies to implementation into clinical practice. Exercise is first line treatment for managing symptomatic hip and knee OA. Aerobic, strengthening and neuromuscular approaches are all effective in reducing pain and improving function. Exercise dose and supervision may be more important. Twelve or more supervised exercise sessions seem superior to fewer sessions. Education about the condition, the role of exercise in reducing pain and improving function, and strategies for increasing physical activity is also key as long-term adherence to ongoing home exercise after program attendance is needed to maintain effects. The proposed mechanisms by which exercise improves pain and function in people with OA include general systemic effects and those local to the joint. General mechanisms include neural and systemic inflammation effects. Local mechanisms include exercise effects on muscle and other joint-related structures as well as local joint inflammation. Exercise effects on pain are as large or larger than for medications such as paracetamol and NSAIDs. Similar magnitude in pain relief and improvement in function from clinical trials has been shown immediately after the program and at 1-year follow-up in evidence-based structured education and exercise programs implemented into clinical practice in several countries. These programs are cost-effective. Although clinicians around the world are slowly adopting exercise as OA treatment, system changes are required to facilitate implementation of evidence-based exercise programs into clinical practice. Enhanced availability of education and supervised exercise programs and reimbursement schemes with support from publicly funded health services that reduce access barriers for patients are needed to support more universal evidence-based management and reduce the burden of symptomatic OA.