Analyzing the effects of cognitive motor interferences (CMI) on walking is usually done in patients with neurological comorbidity or during forward walking (FW). However, there are few studies that examine gait differences between FW and backward walking (BW) under the presence of CMI when speed is kept constant on a treadmill. In this study we examined how CMI would disrupt sensory feedback and affect the descending motor pathway. We hypothesized that subjects that walked backwards and were given a cognitive task would show the greatest differences in gait due to a lack of visual input and the presence of CMI. A three-dimensional motion capture system was used to acquire the movement of the leg and calculate gait characteristics (stride length, stance phase, swing phase). Across the entire population, direction had a significant effect on all gait characteristics, but the presence of CMI did not have a significant effect on any of them. Additionally, there was no significant interaction between the two variables. Specifically, the overall stride was shorter, stance was shorter and swing was longer during backward conditions. However, within subject variability demonstrates that each subject utilizes different strategies to compensate for both the lack of sensory feedback and presence of CMI. Results of this study contradict findings from previous work that direction had no effect on stance and swing phase of walking and suggests that backward walking does change more gait characteristics. This implies that sensory feedback has a large impact on modulating motor output, and these effects may be amplified in those with movement-based neurological disorders like Parkinson’s Disease
