Patellofemoral Pain: an Overuse Injury
One frustrating part of trying to stay fit is the overuse injuries that can strike. I’ve been through physical therapy twice for one of the most common injuries of all: patellofemoral pain, or runner’s knee. Ordinarily the patella, or kneecap, glides smoothly along a groove in the underlying femur. Abnormal tracking forces can cause it to repeatedly contact nearby structures instead, causing pain on the inside of the knee.
I finally have a handle on my own patellofemoral pain and will share what I’ve learned that keeps it settled down. But if you have knee pain start with a visit to a good sports medicine doctor. There are many factors in patellofemoral pain and maltracking, and lots of causes of knee pain outside of that diagnosis.
Knee Pain: Not Always about the Knee
Knee problems aren’t always about the knee itself. Muscles that are tight, weak, or imbalanced in strength compared to nearby muscles can cause problems. Weak ankles or foot pronation can also contribute to knee pain. Your sports medicine doctor and physical therapist can evaluate just where you are weak, tight, or too loose.
In the past, treatment for runner’s knee pain often focused on strengthening the quadriceps muscles on the theory that this would keep the patella tracking properly. But recently more attention has turned to weakness in the hip muscles. How could weak hip muscles cause knee pain?
The muscles of the pelvis control the position of the thigh bone, and therefore the position of the knee. When the knee turns in toward the midline of the body instead of staying aligned over the foot, it’s in a position of greater vulnerability to patellar maltracking. Repetitive maltracking irritates the knee.
Relieving the Stress: Alignment and Strengthening
Proper alignment of the hip, knee and foot alleviates the stress. When you bend your knee, move it in a line over the second toe of the foot. Don’t let it fall to the inside of the foot. To achieve this consistently, you may need to strengthen the muscles that control the knee’s position. You may also need to do movements while watching in a mirror to train yourself to bend the knee in alignment.
One of the muscles that’s frequently weak is the gluteus medius muscle on the side of the hip. Weakness there can contribute to patellofemoral pain. The gluteus medius muscle stabilizes the position of the pelvis when you are standing on one leg, vital when you are doing a sport like running or skating that requires impact, balance, and movement on one leg almost all the time.
Our modern lifestyle doesn’t encourage strong gluteus muscles. Think about it: when you are sitting in a chair, how much work are they doing? And how much time do we spend sitting? Sometimes the gluteus medius becomes so weak that it’s ‘turned off:’ we can’t even consciously fire it to make it work. Other muscles compensate for the weak gluteus medius, but in compensating they create imbalances and misalignments.
Next time I’ll share more of what I learned about managing this problem in PT. Besides strengthening exercises, I do several stretches to manage this problem. My hip flexor stretch is here.
Some useful articles from around the web:
A 1999 American Family Physician article includes a useful table of muscular causes of patellofemoral pain syndrome.
A 2007 American Family Physician article explains the anatomy and biomechanics of patellofemoral pain and gives guidelines for diagnosis and treatment.