Patellofemoral pain syndrome in young women. II. Muscle function in patients and healthy controls.

Clinical alignment, pain variables, common symptoms and functional activity level associated with patellofemoral pain syndrome (PFPS) were evaluated in 40 women with PFPS and 20 healthy controls. No significant difference could be found neither between the patients' most symptomatic knee and least symptomatic knee, nor between the patients and controls regarding clinical lower extremity alignment, such as Q-angle and leg-heel alignment measurements. There were no radiographic signs of malalignment. The patients were significantly more involved competitively in sports but had a significantly lower pain free activity level than the controls. Pain was associated with increased activity. It is suggested that chronic overloading and temporary overuse of the patellofemoral joint, rather than malalignment, contribute to patellofemoral pain.