Patellofemoral pain is a common knee problem.
If you have this condition, you feel pain under and around your kneecap. The pain can get worse when you're active or when you sit for a long time. You can have the pain in only one knee, or you can have pain in both knees. The exact cause of patellofemoral pain isn't known. Take a break from physical activity that causes a lot of pounding on your legs, like running, volleyball, or basketball.