Your kneecap (patella) sits over the front of your knee joint. As you bend or straighten your knee, the underside of the patella glides over the bones that make up the knee.
Strong tendons help attach the patella to the bones and muscles that surround the knee. These tendons are called:
The patellar tendon (where the kneecap attaches to the shin bone)
The quadriceps tendon (where the thigh muscles attach to the top of the kneecap)
Anterior knee pain refers to a number of different conditions. These include runner's knee (sometimes called patellar tendinitis) and chondromalacia of the patella.
Anterior knee pain is more common in:
Adolescents and healthy young adults, especially girls
People who are overweight
Runners, jumpers, skiers, bicyclists, and soccer players, who exercise often
The pain often comes from strained tendons (tendinitis) and irritation or softening of the cartilage that lines the underside of the kneecap (chondromalacia patellae).
These problems begin when the kneecap does not move properly and rubs against the lower part of the thigh bone. This may happen because:
You have flat feet
The kneecap and the two other bones that make up the knee joint don't line up well (this is called poor alignment of the patellofemoral joint)
There is tightness or weakness of the muscles on the front and back of your thigh
You've done too much activity, which places extra stress on the kneecap (such as running, jumping or twisting, skiing, and playing soccer)
Other possible cause of anterior knee pain include:
Dislocation of the patella, which means the kneecap has been pulled out of place
Fracture of the kneecap
Pinching of the inner lining of the knee with knee movement (synovial impingement, or plica syndrome)
Anterior knee pain is a dull, aching pain that is most often felt:
Behind the kneecap (patella)
Below the kneecap
On the sides of the kneecap
Symptoms may be more noticeable with:
Deep knee bends
Going down stairs
Standing up after sitting for a while
Treatment of anterior knee pain involves resting the knee and not running until you can do so without pain.
Apply ice. Try acetaminophen or ibuprofen for pain and swelling (but you may want to check with your health care provider first).
Tests such as x-rays or MRI scans are rarely needed.
Surgery for pain behind the kneecap (anterior knee pain) is rarely needed.
Call immediately for emergency medical assistance if
Call your health care provider if knee pain does not go away, in spite of resting the joint.
Stretch the muscles on the back (hamstrings) and front (quadriceps) of your upper leg.
Your primary care provider, a sports medicine specialist, or a physical therapist can show you stretches to try.
Before you stretch, warm up for 5 minutes.
Also stretch after you are done exercising.
Your health care provider can also teach you ways to strengthen these muscles. Stronger muscles will help hold your kneecap in the correct position.
If you need to lose weight, find out how.
Changing the way you exercise may help:
Avoid running straight down hills; walk down instead
Bicycle or swim instead of running
Reduce the amount of exercise you do
Run on a smooth, soft surface, such as a track, rather than on cement
Other techniques are:
Special shoe inserts and support devices (orthotics) may help people with flat feet
Taping to realign the kneecap can help prevent symptoms
Make sure your running shoes:
Are made well
Have good cushion
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Dixit S, DiFiori JP, Burton M, Mines B. Management of patellofemoral pain syndrome. Am Fam Physician. 2007;75:194-202.
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Steiner T, Parker RD. Patella: subluxation and dislocation: 2. Patellofemoral instability: recurrent dislocation of the patella. In: DeLee JC, Drez D Jr., Miller MD, eds. DeLee and Drez's Orthopaedic Sports Medicine. 3rd ed. Philadelphia, Pa: Saunders Elsevier;2009:chap 22:sect C.
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; and C. Benjamin Ma, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.