Runner's Knee (Patellofemoral Stress Syndrome)
Runner's knee, a pain in the knee joint, is a very common sports injury. In many cases, no cause can be found; in others, overpronation, a tendency for the feet to roll too far inward, plays an important role. In a normal running gait, the heel lands first, and as the foot moves forward, body weight is transferred to its outside edge. The foot then rolls inward, transferring weight to the inside. This pan of the cycle is pronation, which distributes the force of each foot strike throughout the entire foot and leg and protects against injuries.
Excessive pronation results in an exaggerated inward twisting of the lower leg which causes the kneecap (patella) to rub against the thigh bone (femur). In time, this action produces pain behind the kneecap, especially when running downhill. If the condition is not corrected, walking will eventually become painful.
Weak ankles are often responsible for excessive inward rotation of the foot, and wearing the wrong running shoes can worsen the problem.
Diagnostic Studies and Procedures
A doctor will examine the feet and ankles and observe how the patient stands and walks barefooted. A foot that appears flat signals overpronation. A doctor may also examine a patient's shoes, particularly a pair worn for running. People who overpronate wear down the outside back of the heel first.
X-rays may be ordered to rule out arthritis and other joint conditions. Sometimes, the interior of the knee will be examined with an arthroscope, a flexible viewing tube with a lighted tip and magnifying devices. However, this procedure usually is not necessary for a case of runners knee when there have been no previous problems.
Medical Treatments
Aspirin or a stronger nonsteroidal antiinflammatory drug may be prescribed to relieve pain and reduce inflammation. Successful treatment mandates not running until the knee pain has disappeared, and undergoing physical rehabilitation (see Alternative Therapies) before gradually starting again.
Alternative Therapies
Acupressure. Pressing on pressure points on both sides of the knee joint may provide temporary relief.
Alexander Technique. An instructor can analyze your gait and leach you the correct posture and motions to minimize stress on your knees.
Hydrotherapy. Applying ice reduces swelling and inflammation and provides temporary relief from pain.
After a few days of cold packs, some people find that switching to hot compresses, warm water soaks, or a whirlpool bath provides more relief than ice. During rehabilitation, exercising in water may be advisable, because its buoyancy and cushioning effect minimize stress on the knee joint.
Physical Therapy. Ideally, rehabilitation should be directed by a physical therapist who specializes in sports injuries and will have a variety of techniques to reduce pain. The therapist can design an exercise program that will strengthen the quadriceps muscles, which support and protect the knee, and utilize proper running gait and warm-up and cool-down exercises.
Self-Treatment
If knee pain strikes, stop running immediately and refrain from exercises that place extra demands on your knees until you are free of all pain. When you do return to running, try wearing an elastic bandage or a knee sleeve for compression and support. Ankle supports also may be advisable.
Wear the right shoes; the wrong ones could be the root of the problem. Certain models are designed specifically for people who overpronate; among their features are a special arch support and a flared heel for stability. Some runners with knee problems may be helped by additional arch supports designed for running shoes; others may need orthotics, custom-made shoe inserts that can be obtained through a podiatrist or orthopedist. Orthotic devices may be rigid or flexible and usually have posts under the heel to prevent the foot from rolling too far inward.
Other Causes of Knee Pain
Various types of arthritis can cause knee pain. Runner's knee is sometimes confused with chondromalacia of the patella, a softening and inflammation of the cartilage that lines the inside of the kneecap. Running or any other sport that requires repeatedly bending the knee can cause this problem, which is treated with many of the techniques used for runner's knee.