EFFECTS OF FORWARD AND BACKWARD RUNNING ON PATELLOFEMORAL JOINT REACTION FORCE DURING SLOW RUNNING

Abstract

1810 Patellofemoral pain syndrome (PFPS) is a very common result of participation in a variety of exercise and sport activities. Conservative rehabilitation including strengthening, flexibility, and endurance training has always been the preferred treatment compared to surgery. Regarding endurance training, forward running has been prescribed for patients with PFPS. Recently, backward running has been suggested as a form of endurance training which decreases patellofemoral joint reaction force (PFJRF) in comparison to forward running. The purpose of this study was to determine the effects of forward and backward running on patellofemoral joint reaction force. Ten volunteer runners between the age of 20-25 (x = 22 ± 2.00) ran on a laboratory runway, with timing lights to insure running velocity, in forward and backward directions at 2.3 mph (1.0 m-s−1). Using an inverse dynamic mathematical model, the knee extensor moment (KEM) and the PFJRF were calculated for backward and forward running. The results showed no significant differences in KEM and PFJRF between forward and backward running. The PFJRF and KEM were 3.5BW and 144.50 Nm, respectively, for backward running and 3.40BW and 141.60 Nm, respectively, for forward running. In conclusion, slow backward and forward running place similar PFJRF and KEM on the patellofemoral joint, therefore, the preference of the therapist or clinician to prescribe backward running over forward running is not warranted. The velocity of running would be a better deciding factor for the running endurance component of the conservative treatment of PFPS.