Virtual obstacle-avoidance training using daily-life obstacles with physical feedback in older people: A cross-over trial.

Failures in avoiding environmental hazards can lead to falls. We developed a virtual reality (VR) obstacle-avoidance training system that provides physical feedback upon foot contact with a virtual obstacle. This study aimed to assess whether physical feedback reduces obstacle collisions in older adults within a VR environment. Fifty-six participants (mean age 72.3 ± 5.4 (SD) years) wore an immersive VR head-mounted display and safety harness and walked on a split-belt treadmill in two 8-minute conditions performed in random order. They walked on a virtual suburban footpath, collecting virtual apples and avoiding slip-and-trip obstacles. In the perturbation condition (VR+P), foot-obstacle collisions were accompanied by immediate physical feedback via treadmill belt accelerations/decelerations. In the non-perturbation condition (VR-only), no physical feedback was provided. Obstacle collision rates and subjective acceptability were assessed. In the VR+P condition, participants had fewer obstacle collisions (0.63 versus 0.75), fewer trailing foot collisions (0.57 versus 0.68) and a greater margin of stability compared with the VR-only condition (p < 0.05). Participants reported significantly higher levels of anxiety and greater task difficulty for the VR+P condition (p < 0.05). Motion sickness was rarely reported, and enjoyment ratings were high, with no significant differences between the conditions. In summary, physical feedback reduced obstacle collisions and increased gait stability. The low levels of motion sickness and anxiety and high levels of enjoyment reported suggest that VR obstacle avoidance training is highly acceptable to older people. Future research is required to determine the generalisation of improved motor skills to real-world scenarios.