Patellofemoral Pain Syndrome (PFPS)

Knee pain is a very common presenting complaint in a chiropractic office. Patellofemoral syndrome is one of the more common reasons. With this condition patients will often complain of a dull achy diffuse pain in the front of the knee around the knee cap. The condition usually becomes worse with prolonged weight bearing and activity. Stairs are often painful with going down the stairs worse than going up. This is also a condition commonly found with runners.

Several biomechanical factors can be responsible for the development of patellofemoral syndrome. It is important to note that this is a condition that will develop gradually over time and therefore there is no quick fix for the condition but it can be successfully treated. The most common theory of the cause of patellofemoral syndrome is that biomechanical factors lead to the patella (kneecap) shifting laterally or being pulled to the outside of the leg. This has been attributed to weakness of the vastus medialis obliquus muscle (VMO) which is the inside muscle at the front of the leg and an increased Q angle which is the angle created between the hip and the knee. This is why this condition may be more common in women than in men. More recent research on the condition contradicts this theory and points toward abnormal motion of the femur (upper leg bone) as the cause. In summary, rather than the patella shifting into the femur in fact the patella remains stable and the femur rotates abnormally into the patella.

In the past treatment has included taping to stabilize the patella, prescription of medial quadriceps strengthening exercises and even bracing. These treatments have met with variable results. In light of the newest theory regarding patellofemoral syndrome attention has now been directed at hip weakness as a more likely cause and therefore attention to strengthening the muscles around the hips has become the emphasis. One particular study showed very clearer that runners with weak hip abductors had abnormal ranges of internal femoral rotation during the stance phase of gait and that this internal rotation also increased with fatigue.

One of the clinic tests used to determine if there is weakness in the hip abductors is the dynamic single leg squat test. As the name implies, the patient balances on one leg and then attempts to perform a single leg squat. The test is considered positive if the knee moves medially (inwardly) excessively indicating weakness in the hip muscles. It is difficult to perform this test accurately on your own but one might attempt to observe oneself in a full length mirror or have a partner watch as the test is attempted. If excessive inward movement of the knee is observed than weakness of the hip abductors could be a contributing factor for existing knee pain or equally important indicate a predisposition for developing the condition.

Several exercises are affective for strengthening the muscles in question. These include the “clam shell” exercise, squats and lunges. I am commonly confronted by patients with knee pain when I suggest squats and lunges to them with the comment that they can’t do them because they cause knee pain. There in lies the problem. These are normal important movement patterns that normally healthy individuals should be able to do. If one can’t do them it is because there is a weakness and they need to be taught to do the exercise properly. When properly performed even those with knee pain should be able to do the exercises provided that it is at the appropriate stage of rehabilitation. For those in doubt please note that many of these exercises are the very same exercises given to those after knee surgery for rehabilitation. If they are appropriate in that circumstance than they are more than likely appropriate in less severe injuries.

The important point is that the exercises must be done correctly. In many cases consulting with a chiropractor, physiotherapist or other musculoskeletal expert is advisable. These professionals can properly diagnose and treat the problem.