Pedaling a stationary ergometer has been used for rehabilitation of a variety of knee disorders such as anterior cruciate ligament (ACL) reconstruction and patellofemoral pain (PFP). Pedaling has been used due to reductions in ACL strain and compressive loading of the knee joint compared to full weight bearing rehabilitative exercises. Another commonly used rehabilitation technique has been backward gait, since it provides several advantages similar to pedaling when compared to forward gait. Recently, investigators have suggested that similar to gait, backward pedaling might offer similar advantages over conventional forward pedaling. However, these recommendations have been made largely by extrapolating the results found in gait and applying these results to pedaling, rather than basing these recommendations on an understanding of the mechanics of backwards versus forward pedaling. Recently, the journal Clinical Biomechanics published a study by Richard R. Neptune, PhD and Steven A. Kautz, PhD that used forward dynamic simulations of forward and backward pedaling in order to determine whether backward pedaling offered theoretical advantages over forward pedaling to rehabilitate common knee disorders (Neptune RR, Kautz SA: Knee joint loading in forward versus backward pedaling: implications for rehabilitation strategies. Clinical Biomechanics 15(7):528-535, 2000). This work was an outgrowth of NIH-funded work (NIH grant NS17662 to Felix E. Zajac, PhD) and also supported by the Rehabilitation R&D Service of the Department of Veterans Affairs. Drs. Neptune and Kautz found that backward pedaling offers reduced tibiofemoral compressive loads for those patients with knee disorders such as menisci damage and osteoarthritis. However, backward pedaling results in higher patellofemoral compressive loads, so that it is not recommended for patients experiencing patellofemoral pain. Backward pedaling also offers lower protective anterior-posterior shear force, which implies it should not be recommended after anterior cruciate ligament injury or reconstruction. Thus, the results of this study indicate that the design of rehabilitation programs including pedaling exercises should be injury specific with particular attention paid to the mechanics of the task. This study was featured at the American Physical Therapy Association's website in their PT Bulletin Online (Vol 1, Issue 22) in the "What's New in the Literature" section. |
