A teenager who is active in sports and starts to feel a dull, aching pain behind the kneecap (patella) on either or both legs may need to adjust his or her training routine. Chronic pain in the front and center of the knee (anterior knee pain) is common among active, healthy young athletes, especially girls. It does not mean that you will damage your knee by continuing to do activities. You will just hurt more.

Treatment for pain behind the knee cap usually helps and surgery is not usually necessary. Pain below the kneecap (on the upper shin) is a different problem not discussed here.

The complex anatomy of the knee joint that allows it to bend while supporting heavy loads is extremely sensitive to small problems in alignment, training, and overuse. Pressure may pull the kneecap sideways out of its groove, causing pain behind the kneecap. In teenagers, a number of factors may be involved.

• Imbalance of thigh muscles that support the knee joint
• Poor flexibility
• Problems with alignment
• Using improper sports training techniques or equipment
• Overdoing sports activities

A direct blow can also cause pain behind the kneecap. See your doctor to diagnose the cause of pain behind your kneecap and to get treatment.

You may be able to prevent recurrences of pain behind the kneecap. Recommendations include:

• Wear shoes appropriate to your activities.
• Warm up with stretching exercises before physical activity.
• Stop doing any activity that hurts your knees.
• Limit the total number of miles you run in training and competition.

The pain usually begins gradually. You might hear popping or crackling sounds in the knee when you climb stairs or stand up and walk after prolonged sitting. Pain might flare up when you do activities that repeatedly bend the knee (i.e., jumping, squatting, running, and other exercise) and at night. Without treatment, you may also develop thigh muscle (quadriceps) weakness. Your knees could begin to buckle or give way from pain.

To help your physician with making the diagnosis, tell him or her when your knee pain started and provide details about your sports participation and training.

Were there any recent changes to the duration, frequency or intensity of your activities? Are there any alterations in your equipment or the surfaces you play upon?

What activities aggravate your knee pain?

A standard knee examination will help your doctor determine the cause of pain behind your kneecap and rule out other problems. He or she may ask you to stand, walk, jump, squat, sit, and lie down. It's important to relax!

Your doctor may check:

• Alignment of the lower leg, kneecap, and quadriceps
• Knee stability, hip rotation, and range of motion of knees and hips
• Under the kneecap for signs of tenderness
• The attachment of thigh muscles to the kneecap
• Strength, flexibility, firmness, tone, and circumference of thigh and hamstring muscles
• Tightness of the heel cord and flexibility of the feet

Both of your legs may be X-rayed.

Ice, rest, and rehabilitation are the usual treatments for teenagers with pain behind the kneecap. Nonsteroidal anti-inflammatory drugs (NSAIDs), like ibuprofen, may also help particularly painful episodes.