Managing hip and knee osteoarthritis with exercise: what is the best prescription?

Hip and knee osteoarthritis are common, chronic, and disabling. Therapeutic exercise is a component of all major rheumatologic society guidelines, yet the frequency, dose, duration, and therapeutic threshold for exercise are not clearly delineated. This review summarizes current studies of exercise for hip and knee osteoarthritis, discusses issues that influence the design, interpretation, and aggregation of results and how these factors impact the translation of data into clinical practice. A review of databases to identify current randomized controlled trials (2000 to present) of exercise to manage the symptoms of hip and knee osteoarthritis is discussed here. One study enrolling only hip patients was identified. Six studies of outcomes for individuals with hip or knee osteoarthritis and 11 studies of persons with knee osteoarthritis were found. Limited studies focus specifically on exercise for persons with hip osteoarthritis. Exercise is provided as a complex intervention combining multiple modes and provided in various settings under a range of conditions. Regardless of the variability in results and inherent biases in trials, exercise appears to reduce pain and improve function for persons with knee osteoarthritis and provide pain relief for persons with hip osteoarthritis. Given the complexity of exercise interventions and the specific issues related to study design, novel approaches to the evaluation of exercise are warranted.