Knee joint loading in forward versus backward pedaling: implications for rehabilitation strategies

Objective. To use forward dynamic simulations of forward and backward pedal ing in order to determine whether backward pedaling offers theoretical adva ntages over forward pedaling to rehabilitate common knee disorders, Design. A comparison of knee joint loads was performed during forward and b ackward pedaling. Background Pedaling has been shown to be an effective rehabilitation exerci se for a variety of knee disorders. Recently, backward gait has been shown to produce greater knee extensor moments and reduced patellofemoral joint l oads compared to forward gait. But to date, no study has examined the effic acy of backward pedaling as a safe alternative to forward pedaling in rehab ilitation programs. Methods. A musculoskeletal model and optimization framework was used to gen erate simulations of forward and backward pedaling. Tibiofemoral and patell ofemoral joint reaction forces were quantified. Results. Lower tibiofemoral compressive loads, but higher patellofemoral co mpressive loads, were observed in backward pedaling. Lower protective anter ior-posterior shear force was observed in backward pedaling near peak exten sion. Conclusions. Backward pedaling offers reduced tibiofemoral compressive load s for those patients with knee disorders such as menisci damage and osteoar thritis, but higher patellofemoral compressive loads. Therefore, backward p edaling is not recommended for patients experiencing patellofemoral pain. F urther, backward pedaling should not be recommended after anterior cruciate ligament injury or reconstruction. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.