PATELLO-FEMORAL SYNDROME
"knee-cap" PAIN

The patella, commonly referred to as the "knee cap", and its tendon transmit power from the quadriceps to the lower leg. Normally, as the knee bends, the patella slides smoothly along a groove in the thigh bone. However, under certain conditions the patella may experience forces which push it against the sides of the groove, causing pain. Additionally, inflammation and roughening of the smooth underside of the patella may occur. Collectively, this process is referred to as patellofemoral syndrome (PFS). Some of you may be familiar with the older term, chondromalacia patella.

PFS is one of the most common causes of knee pain in runners. The pain is usually located in the front part of the knee, but may be on the inside, outside, or vaguely located. The pain can feel either sharp or dull, and is often made worse by squatting or walking down stairs. Sometimes there is grinding or clicking. Predisposing factors include,

• Training errors - excess hill work, stairs, or too much distance
• Biomechanical abnormalities - overpronation, "knock knees", poor pelvic control
• Muscle tightness - calf, hamstrings, iliotibial band, or vastus lateralis.
• Muscle weakness - vastus medialis obliquus (VMO), gluteus

Treatment

involves rest, ice, anti-inflammatory medications, and taping. Taping can supply immediate pain relief and helps correct abnormal positioning of the patella. It is continued until stretching and strengthening exercises re-balance the patella. Soft tissue therapy and stretching help loosen tight structures. The exact stretch depends upon which muscles are tight. Once pain has resolved then strengthening exercises can be started to prevent the condition from returning.

A frequent finding in runners with PFS is a weak VMO muscle. Isolating and strengthening this muscle will help keep the patella in its groove and there are several useful exercises that accomplish this. All should be done without pain.

• Sit on the floor and place a rolled up towel under your knee. Rotate your leg so that your foot is pointing out at about 45 degrees. Place your fingers over the VMO muscle. Contract the VMO and hold for 30 seconds. Repeat for a set of 5. Practice contracting the VMO first, before the other quadriceps muscles. Your fingers can help give you feedback.
• Step down one stair and back up again. Again, try to isolate the VMO. Repeat for a set of 15 - 20.
  
• Squat, balancing on one leg. Go down until the knee is bent at 90 degrees, and then back up again. Repeat for a set of 15 - 20. This exercise strengthens the VMO and assists in pelvic stability.