Dr. K: Kneecap pain is usually the result of excessive exercise

To understand this condition, here’s a brief anatomy lesson. Sit in a chair, and then lift up your foot (on either leg) and hold your leg straight out. How were you able to do this? A big muscle in the front of your thigh (your quadriceps, or “quads”) is attached to a tough tendon. The tendon is like a cord; it runs over the top of your knee and attaches to the biggest bone in your lower leg, the tibia. When your quadriceps muscle shortens and tugs on the tendon, it lifts up your lower leg and foot.

In the middle of the tendon, right over the knee, is a small bone: the patella, or kneecap. It protects the bones of the knee joint by putting a hard bone in front of them to take the hit if you fall on your knee.

Your patella glides within a groove in the thighbone. Anything that stresses that connection can cause patellofemoral pain.

Patellofemoral pain can occur with one-time overuse (such as several sets of tennis when you haven’t played regularly) or from chronic stress. It’s common in people who run a lot, especially on hills. It’s also common in people who play sports involving jumping, or frequent stops or direction changes. Doctors often see it in people who suddenly start to work out much harder and more often. Certain physical characteristics, such as flat feet, can also contribute.

Pain-free exercise is the cornerstone of treatment. A workout plan to relieve or prevent patellofemoral pain should focus on improving strength and flexibility in the tissues around the knee. (I’ve put a selection of appropriate exercises on my website, AskDoctorK.com.) Work with a physical therapist, who can design an individualized exercise program for you.

While you’re recovering, don’t do anything that causes pain. If you run, avoid hills, go for shorter distances or substitute other activities. Avoid high-impact exercises and squatting or kneeling. Don’t wear high heels or sit with your legs bent for too long.

Ice and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin, others) or naproxen sodium (Aleve, others) can help ease immediate pain. If you have flat feet, you may need additional arch support.

If you’re still in pain after more than one year, you may have to consider surgery. Even then, surgery is recommended only if there is an obvious anatomical problem.

Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.