Patello-femoral syndrome is a relatively common condition which causes pain at the front of the knee. The pain is associated with positions of the knee which result in increased or misdirected mechanical forces between the kneecap (patella) and the thigh bone (femur) (1).
Despite being a common and relatively easy to diagnose injury there is much to learn about the exact pathology involved in the presentation of this condition. There are a number of probable causes which include:
Muscle Tightness (calf, hamstrings, ITB)
Weakness or lack of coordination in muscles that should help maintain normal patella tracking
Altered hip, knee or foot posture
Stability and normal function of the knee joint depends on precise interaction between the muscles, ligaments and fascia which surround and support the joint. Any tightness or weakness can cause an alteration in the normal mechanics which leads to pain. Exercise programs used to treat Patello-femoral pain syndrome should be based on sound biomechanical foundations and sensible exercise progression (2).
The quadriceps muscle group is directly involved in the mechanics of the patella-femoral joint as the patella is enclosed within the quadriceps tendon. Strengthening of the quadriceps is considered to be beneficial. However, the pain of patella-femoral pain syndrome is typically associated with movements which result in strong forces going through the joint so traditional knee extension exercises are not appropriate. Knee extension exercises will stress the already aggravated patella-femoral joint. Therefore, “closed chain exercises” (those where the foot is in contact with a solid surface) are preferred and should initially be performed within a pain free range of motion. Once larger ranges of motion are tolerated without pain, open chain exercises may be introduced. Research data tells us that between 0-50 degrees of knee flexion closed chain exercises produce less stress on the patella-femoral joint, beyond this range open chain exercises produce less stress (2).
Muscle coordination as well as overall muscle strength is important. The vastus medialis oblique (VMO) muscle forms part of the quadriceps muscle group and is the innermost muscle of the group. It is believed to help maintain the knee cap in its correct position (3). Specific focus should be placed on encouraging activity of this muscle when strengthening the overall quadriceps group. When prescribing strengthening exercise, those muscle groups not directly involved in patella-femoral joint mechanics should be considered as well, especially the “core” muscle group.
Concurrently to performing strengthening exercises, those structures which are tight must also be addressed. The calf muscles, hip flexors, hip rotators, and Iliotibial band are all commonly tight where patello-femoral pain is seen. Foam rolling, static stretches, and mobility drills are used to lengthen these tight structures. Full recovery and return to normal function can be achieved if exercises for managing patella-femoral pain syndrome are appropriately chosen and progressed.
For more information about patello-femoral pain syndrome and how Physical Therapy can help you in your recovery from knee pain please contact Steve Messineo at (508) 845-3500 or
1. Associates of physical function and pain in patients with patellofemoral pain syndromme. Piva, SR, Fitzgerald, GK and Irrgang, JJ. 2, 2009, Arch Phys Med Rehabil, Vol. 90, pp. 285-295.
2. Rehabilitation of patellofemoral joint disorders: A critical review. Powers, CM. 5, 1998, JOurnal of orthopaedic and sports physical therapy, Vol. 28, pp. 345-354.
3. Patellofemoral Disorders: A classification system and clinical guidelines for nonoperative rehabilitation. Wilk, KE, et al. 5, 1998, Journal of orthopaedic and sports physical therapy, Vol. 28.