Variability in quasi-steady-state overground walking vs. self-paced treadmill walking

Fixed speed treadmills are commonly used in the clinical and research setting but fail to simulate the variation inherent to natural gait that occurs with overground walking (OGW) at a quasi-steady pace for a high number of gait cycles. The self-paced treadmill (SPT) allows for user-driven variation in the treadmill speed to capture the variations that fixed speed treadmills (FST) fail to replicate. The purpose of this study was to compare the variation of gait parameters during five-minute walking trials for OGW, FST and SPT conditions. The results of this study showed that the variation in OGW speed was statistically equal to the variation in SPT speed for ~26% of the participants and overall, the SPT condition replicated significantly more variation in walking speed. However, gait parameters, such as stride time, showed how the SPT failed to capture certain variation in the OGW condition.