Locomotion Stability Adaptation to the Virtual Reality Induced Sensory Conflicts

Topic: Sensory system conflicts caused by virtual reality immersion may lead to alteration and adaptation in gait characteristics. The current study investigated such effect from the aspect of dynamic stability during walking. Experiment: Twelve healthy elderly took a one-minute treadmill walking experiment. Participants were randomly assigned to regular walking (RW) and virtual reality (VR) walking conditions. Data Analysis: Gait parameters were extracted from the kinematic data. Dynamic stability quantified by the maximum Lyapunov exponent was computed with both the embedded state space and the natural state space for six locations at lower extremities. Results: With the natural state space, the VR group was less stable than the RW group (p<0.0001). Joint instability increased with its vertical distance to the body COM (p<0.0001). The VR group’s medio/lateral distance between ankles contained more high frequency and small amplitude fluctuations than the RW group, which may contribute to the instability of their gait cycles.