Stable or able? Effect of virtual reality stimulation on static balance of post-stroke patients and healthy subjects

Over the last decades, virtual reality (VR) emerged as a potential tool for developing new rehabilitation treatments in neurological patients. However, despite the increasing number of studies, a clear comprehension about the impact of immersive VR-treatment on balance and posture is still scarce. In the present study, we aimed to investigate the effects of VR cues on balance performances of subjects affected by stroke, age-matched healthy subjects, and young healthy subjects. Fifteen patients with sub-acute stroke, fifteen healthy elderly subjects and fifteen healthy young adults took part in this study. All groups were immersed in a CAVE system on a stabilometric platform. The experiment consisted in fourteen trials: (i) ten VR trials, which differed in term of speed and movement direction; (ii) two-stabilometric static sessions, with opened and closed eyes (one at the start and one at the end of the experimental session). Results showed that VR trials increased the sway path length (representative of the body sway amplitudes), in young subjects. Elderly and patients showed less changes in postural sway during virtual reality stimulation than young group. These findings may suggest that a physiological postural performance is not simply evaluable assessing stability, but also assessing the ability of adapting body oscillations to the external stimuli.