femoropatellar syndrom

Patellofemoral Joint Syndrome

"My knee hurts with stairs, when I keep it bent too long, or with sporting activities." "I have pain in the front of my knee with squatting and kneeling"

If these complaints sound all too familiar, you may be one of the many people suffering from patellofemoral joint syndrome. This condition, characterized by a diffuse ache surrounding the kneecap, affects approximately one of every four persons, with the incidence increasing among the athletic population, in women, and people under 50 years old.

Patellofemoral joint syndrome is the result of inability of the kneecap (patella) to track properly on the end of the thigh bone (femur). Normally, as the knee bends and straightens, it moves up and down in a straight line within a groove at the end of the femur. It is when the patella deviates from this course and begins to track further to the outside of the femur that pain will result.

There are many reasons why some people are prone to developing patellofemoral joint syndrome. Often times a brief period of overuse of the knee joint or an increase in physical activity tends to precede an exacerbation.

The presence of certain anatomical issues is believed to contribute to likelihood of developing patellofemoral joint pain. Women are more likely to develop this condition than men perhaps due to the woman's wider hips, which increase the angle between the thigh and the knee and thus predispose the patella to pull towards the outside. A second anatomical issue that can facilitate incorrect movement of the patella is the position of the patella on the femur. If the patella is positioned slightly higher then normal on the femur, it will tend to deviate from its groove more easily with movement of the knee. And thirdly, flat feet or excessive pronation of the feet is thought to contribute to patellofemoral joint syndrome by creating increased rotation of the bone in the lower leg (tibia), which disrupts the patellofemoral mechanism. With the exception of flat feet whose effects can be reduced by wearing orthotics, these anatomical factors cannot be altered and their contribution to this disorder is debated.

Problems that can be corrected are decreased flexibility of the muscle in the front of the thigh (quadriceps), back of the thigh (hamstrings), calf (gastrocnemius) and outside of the thigh (iliotibial band). Weakness of the quadriceps muscle is also significant in controlling movement of the kneecap. These factors can be altered through exercise.

Once you have developed patellofemoral joint pain, what can you do to alleviate it? First, attempt to avoid any motions or activities, which reproduce the pain. Avoid sitting for prolonged periods with the knee bent, take stairs one at a time, and alter athletic activities to reduce stress on the knee.

Second, begin performing flexibility exercises to stretch the quadriceps, hamstring, and calf muscles, which will improve the ability of the patella to move in a straight line on the femur. The following three exercises are suggested:

Facing the wall, standing about two feet away, place your hands against wall. Step forward with one foot and a bent knee. With both heels on the floor, lean your hips towards the wall while keeping the leg in the back straight to stretch the calf muscle. Hold for a count of 20. Repeat 3 times.


Standing near something that can be used for support, reach back with one hand, grabbing your foot and ankle. Bend your knee and bring your heel up towards your buttocks. Hold for a count of 20. Repeat 3 times.


Sitting on the edge of a bed or sturdy table with one leg off the edge, the other leg straightened on the bed or table, lean towards the straightened leg keeping your back straight. Hold for a count of 20. Repeat 3 times.


As the intensity and frequency of the pain is decreasing and the flexibility of the leg is improving, strengthening of the quadriceps muscle (the muscle on the front of the thigh) should begin. The quadriceps muscle is made up of four divisions. The vastus medialis obliquis (VMO) makes up the innermost portion. The ability of this part of the quadriceps muscle to contract effectively is critical to proper movement of the kneecap. There are several exercises that can be done at home to strengthen the VMO.

In one exercise, sit in a chair with your feet flat on the floor, your affected knee bent at about 30-degrees. Place your hand over the distal belly of the VMO (above the knee and to the inside of the lower thigh). As you then tighten the muscle in the front of the thigh you should feel this portion contract. Hold this contraction for 10 seconds. Repeat this procedure with the knee bent to 60 and 90 degrees, as well as with the leg extended out straight.

A second exercise you can perform involves placing a pillow or towel roll between your knees. This exercise can be completed either seated or lying on your back with both knees bent. Squeeze your knees together and hold for ten seconds. Repeat this exercise ten times.

In another exercise, stand with your back against a wall, with your feet one and one-half to two feet from the wall. Slowly bend your knees and slide to a sitting position as far down as comfortable. Don't allow your knees to move forward of your feet and or you hips to move lower than your knees. Hold for ten to twenty seconds and then return to standing. Repeat five times.

None of the exercises noted here should cause knee pain. If they do increase your pain, stop the exercises or decrease the intensity. It may take up to four to six weeks of consistent exercise to significantly reduce knee pain, improve flexibility, and increase strength. Patellofemoral joint syndrome does not have to impede your activity level. A temporary modification of certain activities as well as consistently performing strengthening and flexibility exercises will get you and your kneecap headed in the right direction!

Be safe and remember to check with your healthcare provider or your physical therapist before you start any program.



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