No Contact Needed: Humans Adapt Their Gait to Suit Legged Robot Companions

Legged robots companions may one day assist humans with everyday tasks, but their possible impact on human gait is unknown. While previous studies have shown that humans adjust their gait when walking with other humans, it is uncertain whether walking with legged robots would yield similar results. In this study, we measured the gait of healthy participants (N = 14) while they walked alone and with a small quadruped robot. Spatiotemporal and stability gait parameters were calculated to determine whether the presence of the robot affected participants' gait. We found that walking with robots primarily affected measures in the walking direction. Participants walked slower and with altered anterior-posterior stability with the robot, but we did not find significant differences in the mediolateral direction in terms of step width or stability. However, we also observed that variability in the mediolateral distance between the robot and our participants also influenced participant gait behaviour. Our results demonstrate that robots do influence human gait even without physical contact and through seemingly innocuous actions such as walking near them.