Does land-based exercise reduce joint pain or improve physical function and quality of life in patients with knee osteoarthritis?
Land-based exercise programs reduce knee pain and improve quality of life and physical function following treatment in patients with knee osteoarthritis. (Strength of Recommendation: A, based on consistent, good-quality patient-oriented evidence.)
Osteoarthritis of the knee is a degenerative disease of the joint involving the articular cartilage and underlying bone. Osteoarthritis is the most common form of arthritis, affecting nearly 27 million persons in the United States.1 As the population ages and the prevalence of obesity increases, the prevalence of knee osteoarthritis and its impact on pain and physical function are expected to increase as well.1 Although no cure exists, exercise is a nonpharmacologic therapy commonly recommended for patients with osteoarthritis.2,3
This updated systematic review includes 54 studies of patients with mild to moderate symptomatic knee osteoarthritis. Land-based exercise therapy consisted of nonaquatic muscle strengthening, functional training, or aerobic conditioning programs, ranging from individually delivered programs to class-based or home programs. Exercise moderately reduced pain (44 studies with 3,537 patients; standardized mean difference [SMD] = −0.49; 95% confidence interval [CI], −0.39 to −0.59); moderately improved physical function (44 studies with 3,913 patients; SMD = −0.52; 95% CI, −0.39 to −0.64); and slightly improved quality of life (13 studies with 1,073 patients; SMD = 0.28; 95% CI, 0.15 to 0.40) immediately after treatment. Improvement was sustained two to six months posttreatment for pain (12 studies with 1,468 patients) and physical function (10 studies with 1,279 patients).
Subgroup analyses of exercise programs (quadriceps strengthening, lower limb strengthening, combination strengthening, walking programs, and other programs) found improvements in pain and physical function, with no differences among the various programs. Similarly, there were no statistically significant differences in pain or physical function among the three exercise delivery modes (individual, class-based, and home programs) or in the number of treatment contact occasions (fewer than 12 occasions vs. 12 occasions or more).
Only four of the randomized controlled trials reported blinding patients to treatment allocation; participants in all trials self-reported pain, physical function, and quality of life. Despite the lack of blinding and risk of performance and detection bias, these factors were not thought to affect the quality of evidence or findings. Eight studies reported adverse effects related to increased knee or low back pain among patients in the exercise group. However, none of these were considered serious.
The benefit of land-based exercise for osteoarthritis pain described in this review is comparable to that of previously reported estimates of nonsteroidal anti-inflammatory drugs for knee pain.4 Because exercise programs varied markedly among studies, a range of land-based exercise programs can be recommended in clinical practice. Current guidelines by the American College of Rheumatology strongly recommend that all patients with symptomatic knee osteoarthritis be enrolled in an exercise program that matches their ability to participate in the required activities, with no preference for aquatic vs. land-based programs.3