The effect of open and closed chain exercise and knee joint position on patellar tracking in lateral patellar compression syndrome.

There are numerous rehabilitation protocols for patellofemoral problems, but there is little objective data to determine the most effective exercise program to conservatively treat this disorder. The purpose of this study was to determine the effect of open and closed chain exercise and knee joint position on patellar tracking in lateral patellar compression syndrome. Computed tomography scans of the patellofemoral joint were performed with the leg in three muscle conditions and at five knee angles in 16 subjects with lateral patellar compression syndrome. Patellar tracking was evaluated by measuring congruence angle. Relaxed and closed chain conditions demonstrated improved congruence as compared with the open chain condition at 0, 10, and 20 degrees of knee flexion (p < .0001). Open chain strengthening techniques appear to be most appropriate after 30 degrees of knee flexion. The three muscle conditions demonstrated progressively improved patellar congruence from 0 to 40 degrees of knee flexion.

The effect of exercise on patellar tracking in lateral patellar compression syndrome.

The influence of a physical therapy program on pain and patellar tracking was investigated clinically and radiologically with tangential views in 51 knees with lateral patellar compression syndrome. A pretest-posttest design was used to evaluate physical measurements of patellar alignment in subjects who had had patellofemoral pain for a minimum of 6 weeks. Eighty-four percent of the subjects were pain-free after an average of 8 weeks of rehabilitation or 11 physical therapy visits, with a mean quadriceps strength to total body weight ratio of 61% in women and 86% in men. The pretest-posttest difference in Merchant's congruence angle was significant at a probability of 0.0066 in the patients who were pain-free after exercise, demonstrating less lateral patellar tracking. The pretest-posttest difference in iliotibial band flexibility was significant at a probability of 0.0017, with the patients who were pain-free after exercise becoming more flexible. No significant differences were observed from before to after exercise in the patellofemoral index, Q angle, hamstring flexibility, thigh measurement, sclerotic subchondral bone, or sulcus angle. We were unable to predict which subjects would become pain-free with exercise by patellar position because the group that improved began more laterally tilted. The results of this study indicate that patellar tracking is improved with vastus medialis oblique strengthening, iliotibial band stretching, and joint mobility exercise in the majority of subjects with lateral patellar compression syndrome.