Balance Training in Virtual Reality: Influence of the Frequency and the Amplitude of the Environment Motion on Body Sway

How humans solve sensory conflict during balancing tasks can impact their ability to stand and to prevent falls. Over-reliance on the visual system is common among people with neurological disease and can be reduced with balance training in Virtual Reality (VR). Specifically, environment motion in VR can be used as perturbation, where two main parameters can be tuned: frequency and amplitude. In this work, we systematically tested 18 different pairs of parameters, to find the one inducing the largest body sway. With a head-mounted VR display, a room scene with sinusoidal motion patterns was played while healthy young participants stood still on foam or on a balance board. 18 trials of one minute were performed. The largest body sway, measured through the displacement of the center of mass, was obtained with {0.25 Hz; 5 m/s} for both surfaces. This study promotes the importance of carefully tuning VR parameters to optimize balance training.