Although it may be argued that individually supervised exercise programs are preferable to home- or group-based sessions, the most appropriate number of individually supervised sessions to provide is unclear. Fransen and colleagues found a significant difference between studies providing 12 or more sessions compared to those providing fewer than 12 sessions, but this difference was no longer significant after removing extreme outliers.2 Another review noted that exercise interventions are more beneficial when provided at least three times per week.8
Mode: Prior studies have included a variety of exercise modes, but most employ treatment programs consisting of both aerobic and resistance exercise. Few studies have directly compared aerobic vs. resistance exercise in knee OA.9
A recent pilot trial found that a cognitive-behavioral intervention may be superior to traditional exercise therapy in improving physical activity in sedentary individuals with knee OA over one year.
It’s likely that severity of OA symptoms plays a role in tolerance to certain modes of exercise. Although one study noted no significant difference between weight-bearing and non-weight-bearing lower extremity resistance exercise, weight-bearing exercise may not be well tolerated by some with knee OA due to increased joint loads.10 However, multi-joint weight-bearing aerobic or resistance exercise may be more functional and can assist in maintenance of bone mineral density. Because current evidence has not yet clearly delineated the optimal mode of exercise for patients with knee OA, exercise prescription should be patient specific, considering the patient’s tolerance for pain-free movement and weight bearing.
Dosage: The proper intensity, frequency and duration of exercise for knee OA have not been determined. Very few studies have actually studied different doses of similar exercises in knee OA. One study found no significant differences between high-intensity and low-intensity quadriceps and hamstring strengthening.10
Two recent Cochrane reviews concluded that “specific recommendations cannot be made regarding optimal dosage” due to “insufficient evidence to determine the effect of different types of intensity of exercise programs.”2,11
Another recent article noted the dearth of published trials in which varying prescriptions of intensity and frequency are directly compared in individuals with OA.12 Clearly, additional research is needed on the topic of optimal dosage of exercise in knee OA.
Because current evidence has not yet clearly delineated the optimal mode of exercise for patients with knee OA, exercise prescription should be patient specific, considering the patient’s tolerance for pain-free movement & weight bearing.
Supplementing Exercise Therapy with Manual Therapy
Manual therapy techniques may include stretching the knee and other lower extremity musculature, mobilization of the tibiofemoral and patellofemoral joints, and soft tissue mobilization techniques. Current ACR clinical guidelines conditionally recommend manual therapy as a supplement to supervised exercise therapy.1 Several studies directly investigating the effects of manual therapy have been published since the release of the most recent ACR guidelines.
