Overview

Patellofemoral (puh-tel-o-FEM-uh-rul) pain syndrome is pain at the front of the knee, around the kneecap. The kneecap also is known as the patella. Patellofemoral pain syndrome is sometimes called runner's knee. It's more common in people who run and who play sports that involve running and jumping.

The knee pain often increases when running, walking up or down stairs, sitting for long periods, or squatting. Simple treatments, such as rest and ice, often help. But sometimes patellofemoral pain needs physical therapy.

Symptoms

Patellofemoral pain syndrome usually causes a dull, aching pain in the front of the knee. The following can increase the pain:

  • Walking up or down stairs.
  • Kneeling or squatting.
  • Sitting with a bent knee for long periods of time.

When to see your doctor

If the knee pain doesn't improve within a few days or it gets harder to move the knee, call your health care provider.

Causes

Patellofemoral pain syndrome can have several causes. It's been linked with:

  • Overuse. Running or jumping sports put repeated stress on the knee joint, which can cause irritation under the kneecap.
  • Muscle imbalances or weaknesses. Patellofemoral pain can occur when the muscles around the hip and knee don't keep the kneecap in line. Moving the knee inward during a squat has been linked to patellofemoral pain.
  • Injury. Trauma to the kneecap, such as when the kneecap gets out of place or breaks, has been linked to patellofemoral pain syndrome.
  • Surgery. Knee surgery can increase the risk of patellofemoral pain. This is especially true of repair to the anterior cruciate ligament using one's own patellar tendon as a graft.

Risk factors

Factors that can increase your risk include:

  • Age. Patellofemoral pain syndrome typically affects teens and young adults. Arthritis is more often to blame for knee problems in older people.
  • Sex. Women are twice as likely as men are to develop patellofemoral pain. This may be because women have wider pelvises. A wider pelvis increases the angle at which the bones in the knee joint meet.
  • Certain sports. Running and jumping sports can put extra stress on the knees. This is especially true when adding more training.

Prevention

Sometimes knee pain just happens. But certain steps may help prevent the pain.

  • Build strength. Strong leg and hip muscles help keep the knee balanced during activity. Avoid deep squatting during weight training.
  • Move safely. Ask a physical therapist about exercises to help you jump, run and turn correctly. It's especially important to strengthen outer hip muscles. This will help keep your knee from caving inward when you squat, land from a jump or step down from a step.
  • Lose excess pounds. If you're overweight, losing weight relieves stress on the knees.
  • Warm up. Before running or doing other exercise, warm up with five minutes or so of light activity.
  • Stretch. Promote flexibility with gentle stretching exercises.
  • Build up slowly. Don't suddenly increase your workouts.
  • Mind your shoes. Wear shoes that fit well and are designed for the activity.
By Mayo Clinic Staff