A biomechanical basis for rehabilitation programs involving the patellofemoral joint

Problems at the patellofemoral joint have long been recognized as a cause of dysfunction at the knee. This is true both when the patellofemoral joint is the primary site of involvement and when injury to other structures or aggressive activity/rehabilitation causes the patellofemoral joint to become involved. The purpose of this article is to review the biomechanics of the patellofemoral joint to facilitate the design of safe, effective, rehabilitation programs. The review of normal patellofemoral biomechanics is followed by general rehabilitation guidelines based on those normal biomechanics. These guidelines can be used to design individualized rehabilitation programs for patients with patellofemoral joint dysfunction, in place of putting all patellofemoral patients on a straight leg program regardless of pathology. Two case studies are presented that incorporate the rehabilitation guidelines that were developed based on normal biomechanics of the patellofemoral joint. One case study reviews the rehabilitation of a patient whose recurrent patellar subluxation is treated with a proximal realignment of the extensor mechanism. The other case study involves a patient with an open reduction internal fixation of a fractured patella. J Orthop Sports Phys Ther 1990;11(11):535-542.