Analysing Balance Loss in VR Interaction with HMDs

Immersive virtual reality (VR) has been used in different fields such as training, educational programs, entertainment, psychological treatments, and rehabilitation. Despite its broad utilization, some issues limit its application such as the loss of balance. Balance is disturbed because visual stimuli received from the virtual scenario are not in harmony with perceived stimuli by the proprioception and vestibular systems that remain in contact with the real environment. With the increasing popularity and accessibility of high-quality VR systems, concerns have been raised about the propensity of VR to induce balance loss. Balance is essential for safe use of VR experience and its loss can result in severe injury. In this work, we present a methodology and the necessary tools to quantify the influence of VR on the user’s balance and assess risk of falls during VR interaction. By means of an experiment making use of an Oculus Rift and a MS Kinect Sensor, we observe, quantify and compare the effect of VR scenes with different levels of danger on the balance of users, as well as the effect of visual and auditory warnings of balance loss. Results suggest that auditory signs were not effective in warning users about risk of fall, and that the order which the scenes are presented to users affects their behavior. Users who were first presented to a more challenging scene proceeded more carefully and most of the time carried this behavior to the other less challenging scenes.