An Electromyographic and Motion Analysis of Forward and Backward Walking

Backward walking is a common intervention in the rehabilitation of lower extremity injuries. Despite its popularity, there is limited research available on the EMG activity during backward walking at an incline when compared to forward walking. In this study, we recorded EMG activity in four muscles of the lower extremity and utilized motion analysis to evaluate the knee range of motion when walking forward and backward on a treadmill at 0 and 15 percent grade inclines. Overall, our results indicated a greater increase in muscle activity during backward walking than forward walking. Walking backward at a 15 percent grade incline showed the largest increase in muscle activity with the vastus lateralis showing increase of 609%, vastus medialis increasing 339%, semitendinosus increasing 189%, and biceps femoris increasing 172% when compared with forward walking at a 0 percent grade. Our results showed the degree of knee flexion to be the greatest during backward walking at a 15 percent grade (70.2 degrees of knee flexion), followed by forward walking at a 15 percent grade (68.4 degrees of knee flexion), forward walking at 0 percent grade (67.4 degrees of knee flexion) and finally backward walking at 0 percent grade (57.5 degrees of knee flexion). We conclude that both backward and forward walking at an incline can be beneficial for lower extremity rehabilitation