Auditory feedback effect of self-pacing treadmill walking in comparison to overground walking

Self-pacing treadmills provide advantages for assessing locomotion, but there are differences between gait patterns in overground and treadmill paradigms. A potential explanation could be that the variable auditory sound from the treadmill belt motors when changing speed provides artificial sensory feedback to walkers that may influence their motor output while on the self-pacing treadmill. We hypothesized that there would be significantly different temporal measures between the sound and no-sound conditions, and these same measures from the no-sound condition would be similar to overground walking. Participants (n=29) walked under three different conditions for five-minute periods each: on the self-pacing treadmill with sound inclusion, on the self-pacing treadmill with sound exclusion, and overground walking. Significant differences were found in the variability of all temporal walking measurements between the overground and both treadmill conditions (p < 0.05). Effects of sound on temporal walking measurements were not observed. The lack of difference between the two treadmill conditions suggests that self-pacing treadmill walkers may not utilize the variable belt motor sounds available to them. Additionally, overground walking still has different gait patterns compared to self-pacing treadmill walking, so other potential sources of differences should be explored in future work. Given that both treadmill conditions had different temporal gait patterns from overground, considerations for using the self-pacing treadmill as an alternative for overground walking should be taken when studying human locomotion.