Patellofemoral pain caused by overactivity. A prospective study of risk factors in infantry recruits.

A prospective study of 390 infantry recruits revealed that the medial tibial intercondylar distance and that the isometric strength of the quadriceps, tested at 85 degrees of flexion of the knee, had a statistically significant correlation with the incidence of patellofemoral pain caused by overactivity. Increased medial tibial intercondylar distance and increased strength of the quadriceps were therefore deemed to be risk factors for this syndrome.