Pseudo-Sensation of Walking Generated by Passive Whole-Body Motions in Heave and Yaw Directions

Walking is an innate human behavior that propels the body forward. Recent studies have investigated the creation of a walking sensation wherein, the body neither moves nor is forced to move. However, it is unclear which whole-body motions effectively induce the sensation of walking. Here, we show that passive whole-body motions, such as heave and/or yaw motions, produced by a motorized chair induced a sensation of walking for seated participants in virtual environments as if the participant were walking while viewing a virtual reality scene through a head-mounted display. Our findings suggest that the passive whole-body motions in the gravitational axis-and to a lesser extent in the yaw axis-provide a clear perception of pseudo-walking, but only with limited motion amplitudes, namely one-fourth or less than those of actual walking. In addition, we found a negative correlation between the scores of walking sensation and motion sickness.