Patellofemoral Pain Syndrome: What's the Hip Got to Do With It?

Patellofemoral pain syndrome (PFPS) is a common cause of knee pain in sports athletes. For a long time it was believed that the kneecap (patella) was off kilter in PFPS. As it moved up and down in its track over the knee joint, the patella slipped off to the side.

But scientists have been able to show that the hip may be part of the problem. In this study, physical therapists test hip strength and flexibility in 35 patients with PFPS. A six-week program of hip exercises was prescribed.

Strength, flexibility, and clinical tests were performed before and after treatment. Level of pain was also measured before and after. Results were compared with the following findings:

  • Patients with PFPS had decreased hip flexion and abduction strength before the exercise program.
  • Some but not all patients had decreased pain with daily activities after treatment.
  • Strength improved in patients who had a successful result after six weeks of exercise; hip flexion strength did not improve in those patients who did not have a good result.
  • Patients who had a 20 percent or greater improvement in hip flexion strength were more likely to have a successful outcome.
  • Patients with positive results were more likely to have increased hip flexibility after treatment; a small number of patients (two out of eleven or 18 percent) had treatment success but still had tight hip flexors.

    This study confirms the importance of hip strength and flexibility in PFPS. It's possible that proper hip flexor strength and flexibility keeps the leg from rotating inward during activities that result in PFPS. Exercises to improve control of the pelvis and hip may be a key to the successful treatment of PFPS.



    References: Timothy F. Tyler, MS, PT, ATC et al. The Role of Hip Muscle Function in the Treatment of Patellofemoral Pain Syndrome. In The American Journal of Sports Medicine. April 2006. Vol. 34. No. 4. Pp. 630-636.