Many people suffer from nagging pain in the front knee area, and may feel as though the pain originates right under the kneecap (patella). This may be a condition known as patellofemoral pain syndrome especially if pain is worse climbing stairs or sitting for long periods of time ("moviegoers sign"). Women are more likely to suffer from this condition due in part to their wider hips affecting the angle between the femur and the patella (Q angle). Quite often pain is noticed in individuals with a history of a previous knee injury and a reduction in size or weakness of muscle a muscle known as the vastus medialis oblique (VMO). This muscle lies just above the kneecap on the inner edge of the thigh and is suspected as being responsible for the stabilization and correct "tracking" of the kneecap in its groove.

A simple way to test for VMO weakness is to tense the quadriceps (thigh muscles) and compare the size of the muscle on one side to the other. If the VMO on the painful side looks smaller or less developed, then this may be a predisposing condition, and it is important to try and strengthen it. Try performing ball squats (a stability ball placed in the small of the back between you and a wall) in a pain-free range of motion or approximately 60-90 degrees of knee bend while squeezing a child's plastic ball or a foam roll between the thighs. Also, try performing adduction exercises (bringing the leg in towards the midline of the body) against resistance (e.g. gravity, rubber band, ankle collar and cable machine). These exercises are suggested since the VMO shares a common tendon with a muscle known as the adductor magnus (causes adduction of the leg).