Patellofemoral Pain: Guidelines from the American Physical Therapy Association

Risk Factors

Decreased flexibility and muscle weakness of the hip and knee are present in PFP, but hip weakness appears to be secondary to PFP instead of a cause. Physically active women are more susceptible to PFP compared with similarly active men. Knee extensor weakness in women increases PFP risk. Women who participate in multiple sports are at lower risk than women participating in a single sport. Measurements of static and dynamic knee valgus, including the Q angle, do not predict PFP risk.

Diagnosis

PFP presents with retropatellar or peripatellar pain on knee flexion, such as with squatting, stair climbing, or prolonged sitting. With this type of pain, these activities are the most accurate diagnostic tests. Lack of pain with squatting makes PFP unlikely. Reduced lateral patellar mobility with patellar tilt testing is highly specific but cannot rule out PFP. Other proposed tests have insufficient accuracy.

Other causes of anterior knee pain have more specific findings. Patellar instability presents with recurrent subluxation or dislocation episodes and apprehension with lateral patellar pressure. Patellar tendinopathy is common in adults,