Knee Pain: Understanding Patellofemoral Syndrome

Spring in Chicago came early this year, and with that many recreational runners took advantage of the weather and returned to running after several months of inactivity or running indoors. Also, many of these runners in their excitement did not progress slowly back into the activity and thus were more susceptible to injuries, including patellofemoral syndrome, which is often referred to as “runner’s knee.”

Patellofemoral syndrome is one of the most common types of knee pain seen in the outpatient setting. It is caused by imbalances in the forces that control the tracking of the patella (kneecap). Forces on the patellofemoral joint range from 1/3 to 1/2 of body weight during walking, 3 times body weight with stair climbing, 5 to 6 times body weight with running, and up to 7 times body weight with squatting.

Risk Factors for Developing Patellofemoral Syndrome:

• Overuse
• Trauma
• Tight lateral structures including lateral quadriceps, iliotibial band, and connective tissue called the lateral retinaculum
• Patellar hypermobility
• Poor quadriceps strength
• Flexibility deficits at the hamstring, iliotibial bands, or quadriceps
• Weakness of hip musculature, particularly gluteus medius
• Lower extremity malalignment
• Excessively worn or inappropriate footwear
• Resuming running after periods of inactivity
• Progressing distance too quickly

Typical Symptoms of Patellofemoral Syndrome:

• Pain behind or around the patella (kneecap) with activities that load the patellofemoral joint including stair climbing, squatting, running
• Usually a gradual onset but may arise following trauma
• May be unilateral or bilateral
• Stiffness or pain following prolonged sitting with the knees bent
• Giving way of the knee

Management of patellofemoral syndrome should include relative rest and a comprehensive rehabilitation program to address the underlying causes. In the early stages of rehabilitation, activities that cause loading of the patellofemoral joint should be temporarily avoided or decreased to a level that does not elicit pain during or within 24 hours after the activity. This includes decreasing distance and frequency of running and eliminating strength training activities that stress the joint such as squats, lunges, or resisted knee extensions. Alternative forms of exercise including swimming, biking, and elliptical trainer can be utilized to maintain fitness while undergoing treatment.

Physical therapy is also an important component in the treatment of patellofemoral syndrome to identify underlying causes and restore function. A physical therapist will perform an evaluation, identify the specific factors causing symptoms, and design an individualized program to address deficits. No one treatment program is effective for all patients as the underlying causes may be different, but some common elements of treatment include:

• Flexibility exercises for the hamstrings, quadriceps, and iliotibial bands
• Quadriceps strengthening
• Gluteal strengthening
• Soft-tissue mobilization
• Joint mobilization
• Balance and proprioceptive (body’s awareness of where it is in space) activities
• Retraining of lower extremity biomechanics
• Education in a return-to-run program

If you have been experiencing symptoms of patellofemoral syndrome, contact a physician to obtain a prescription for physical therapy treatment to get you back on your feet!