February 5, 2010
Dear Mayo Clinic:
What are the best exercises for sufferers of knee pain?
While I can recommend some general exercises and activities — walking, for example — the most beneficial regimen will depend on the cause of the knee pain. Work with your doctor for a definitive diagnosis. Once you know the cause, I strongly advise seeing a physical therapist to learn how to do the exercises recommended for your condition. Learning proper technique from a handout alone can be very difficult.
Knee pain has numerous causes. Two of the most common are osteoarthritis and patellofemoral pain syndrome.
Osteoarthritis: This is considered "wear and tear" arthritis and is associated with aging. It occurs when the cartilage in the knee joint wears down over time. In addition to pain, the knee may feel stiff and tender. Osteoarthritis may limit the range of motion. Inactivity seems to increase pain. Mild activity usually helps, while overdoing it can cause more pain.
Considerable research has found that exercises focused on strengthening the quadriceps (front thigh muscles) and hamstrings (muscles in the back of the thigh) help reduce knee pain from osteoarthritis. Patients need to find the middle ground in exercises that help but don't hurt. Examples of effective exercises include leg lifts and squats. Leg lifts are done by lying on your back and then lifting your leg a few inches off the ground while keeping it straight and holding it for a count of 5 to 10. Squats can be done with your back against the wall, feet shoulder-width apart, and then bending your knees 30 degrees. Hold this position for a count of 5 to 10.
Doing exercises in the swimming pool can be beneficial, as buoyancy reduces stress on the knee. Holding on to the side of the pool and kicking your legs will exercise some of the same muscles as leg lifts and squats.
Patellofemoral pain syndrome: This is caused by abnormal tracking of the knee. The pain is concentrated at the front of the knee. The underlying cause can be overuse, an injury, loss of cartilage on the underside of the patella (chondromalacia), or osteoarthritis changes behind the knee cap. Typically, it's aggravated by walking up and down stairs and by sitting for long periods. Strengthening the muscles along the inner thigh can help decrease pain and realign the knee. Examples include leg lifts that can be done lying on your side or back.
Regardless of the underlying cause of pain, strengthening the muscles surrounding the knee can help reduce that pain. For patients with high levels of pain, the initial focus might be isometric exercises — repetitions of muscle contractions and relaxation done without bending the knee.
Overall, walking helps strengthen the muscles surrounding the knee, as long as the knee pain isn't causing a limp or changes in the person's gait. In that case, walking for exercise could worsen the situation. Other, more tolerable options might include using an elliptical trainer, walking in a swimming pool or perhaps riding a stationary bicycle.
Squats are another great overall exercise — if they don't hurt. Squats strengthen the entire leg and move the body in a way that makes it easier to do daily activities. (Think of picking up a laundry basket or bending down to talk to a small child.) However, some people might not be able to tolerate squats. And, it's important to get advice on proper technique. Doing squats incorrectly can cause problems in the hips, ankles and low back.
Because each individual's pain level, fitness level and underlying medical condition are different, there's no "best of" list of knee exercises. The best advice is to not engage in activities that make the pain worse, and seek medical guidance on muscle strengthening exercises tailored to your situation.
—Matthew Butters, M.D., Physical Medicine and Rehabilitation, Mayo Clinic, Scottsdale, Ariz.