Patellofemoral refers to the kneecap (patella) as it moves over the femur (thigh bone). The patella moves up and down along a specially designed track of cartilage and bone. This holds it in place and gives the knee smooth motion.

Improper foot position can get the patella off track causing painful knee symptoms. Orthotics work by altering muscle function and by changing foot position, which also alters muscle function. Orthotics slip inside a shoe and hold the foot in a neutral position. The idea is to correct abnormal leg alignment and restore proper mechanics. With the foot in the right position, the patella can track normally.

Recently scientists found out orthotics also change the way leg muscles contract. They think nerve sensors in the bottom of the feet respond to the orthotic. Messages are sent to the quadriceps (thigh) and gluteus medius (hip) muscles. PFPS is less when these two muscles are in balance.