What is patellofemoral pain syndrome?

Patellofemoral pain syndrome is pain in the front of the knee. (The patella is the kneecap, and the femur is the thighbone.) It's caused by overuse, weak thigh muscles (quadriceps), or a problem with the way the kneecap moves. Extra weight may also cause this syndrome.

In some cases, the kneecap doesn't move, or track, in a normal way. You may have knee pain when you run, walk down hills or steps, or do other activities. Sitting for a long time also can cause knee pain.

Your knee pain may get better with home care. Exercises to make your quadriceps stronger can also help. Losing weight, if you need to, may also help with pain.

Pain in the front of the knee can also be caused by chondromalacia. In this problem, the underside of the knee cartilage wears down and frays. Cartilage is a rubbery tissue that cushions joints.

The main symptom of patellofemoral pain syndrome is knee pain, especially when you are sitting with bent knees, squatting, jumping, or using the stairs (especially going down stairs). You may also experience occasional knee buckling, in which the knee suddenly and unexpectedly gives way and does not support your body weight. It is also common to have a catching, popping, or grinding sensation when you are walking or when you are moving your knee.

Your doctor can recommend treatments to reduce symptoms. For example, over-the-counter pain medicine, such as ibuprofen, can decrease swelling and pain. A physical therapist can teach you exercises to stretch and strengthen your legs. Taping or using a knee brace can stabilize the kneecap. If these don't help, you and your doctor may choose surgery.

Your doctor will ask about your symptoms and past health and will do a physical exam. You might have an imaging test, such as an X-ray or MRI. These tests show the tissues inside your knee. This can help the doctor rule out other possible causes of your symptoms.

• Ask your doctor if you can give your child acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) for pain. Be safe with medicines. Read and follow all instructions on the label.
• Do not give your child two or more pain medicines at the same time unless the doctor told you to. Many pain medicines have acetaminophen, which is Tylenol. Too much acetaminophen (Tylenol) can be harmful.
• Have your child rest and protect the knee. It can help to take a break from activities that cause pain. These include long periods of sitting or kneeling.
• Put ice or a cold pack on your child's knee for 10 to 20 minutes after activity. Put a thin cloth between the ice and your child's skin.
• If your doctor recommends an elastic bandage, sleeve, or other type of support for your child's knee, put it on as directed.
• If your child's knee is not swollen, you can put moist heat or a warm cloth on the knee. After several days of rest, your child can begin gentle exercise of the knee.
• Help your child reach and stay at a healthy weight. Being overweight puts stress on the knees.
• Have your child wear athletic shoes that offer good support, especially if your child runs.
• Use shoe inserts, or orthotics, if they help reduce knee pain. Many drugstores and shoe stores sell them.
• Take your child to a physical therapist to learn more exercises and stretches to make the legs stronger.

Patellofemoral pain syndrome may be caused by overuse, injury, excess weight, a kneecap that is not properly aligned (patellar tracking disorder), or changes under the kneecap.

Patellofemoral pain syndrome is pain in the front of the knee. It frequently occurs in teenagers, manual laborers, and athletes. It sometimes is caused by wearing down, roughening, or softening of the cartilage under the kneecap.