Symptoms of patellar tracking disorder can include:

• A dull ache under, around, and/or at the outer edges of the kneecap, sometimes called patellofemoral pain syndrome. This is often made worse by using the stairs (especially going down stairs), sitting for long periods, and squatting.
• A popping, grinding, slipping, or catching of the kneecap as the knee bends or extends. A grinding or popping sensation may develop before painful symptoms start or may not occur at all. If you have kneecap popping or grinding without pain, see the Prevention section of this topic for stretching and strengthening exercises.
• Swelling of the knee, in some cases.
• The knee buckling or "giving way," as though the knee suddenly won't support your weight.

Knee pain has many causes. If you have knee pain when you are squatting, standing up from a sitting position, going down stairs, or sitting, you may have patellar tracking disorder. But other conditions cause symptoms similar to those of patellar tracking disorder. For more information on other causes of knee symptoms, see the topic Knee Problems and Injuries.