Patellofemoral Syndrome: Symptoms & Signs

Medically Reviewed on 8/4/2020

Patellofemoral syndrome is the most common cause of chronic knee pain.

Signs and symptoms of patellofemoral syndrome include discomfort or pain in the inner knee area, aggravated by activity (like running, jumping, climbing or descending stairs) or by prolonged sitting with knees in a moderately bent position. Other associated symptoms can include

Cause of patellofemoral syndrome

An abnormality in how the kneecap (or patella) slides over the lower end of the thighbone (the femur). Instead pulling up over the end of the femur in a straight line by the quadriceps (thigh) muscle, in PFS, the kneecap moves further toward the lateral (outer) side of the femur. This results in grating of the underside of the kneecap along the thighbone, causing inflammation and pain.

Other patellofemoral syndrome symptoms and signs

  • Abnormal Walking
  • Knee Stiffness
  • Knee Swelling
  • Muscle Weakness


Medically speaking, the term "myalgia" refers to what type of pain? See Answer

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Jameson, J. Larry, et al. Harrison's Principles of Internal Medicine, 20th Ed. New York: McGraw-Hill Education, 2018.