Posture and Virtual Reality: How a Head-Mounted Display Affects Postural Stability and Plantar Pressure Parameters in Healthy Population

Background: The Postural Control System is affected by sensory inputs in stabilizing posture. The impact of postural receptors can be quantitatively evaluated by baropodometry. The lack of a standardized testing environment can decrease the reliability of baropodometric results. Virtual reality (VR) might represent a useful standardization tool. This study aimed to investigate the effects of virtual environment on plantar pressure and postural stability parameters by using a Head-Mounted Display (HMD). Methods: 50 healthy young adults underwent a baropodometric exam in upright standing under four conditions: Open Eyes (OE), Closed Eyes (CE), open (HMD-OE) and closed eyes (HMD-CE) conditions while wearing an HMD. Results: a negligible effect of VR on intrasubject variability of plantar pressure and stabilometric parameters. Moreover, no significant differences in the latter ones were found between OE conditions without and with headset (OE vs. HMD-OE), highlighting no impact of VR; instead, a significant increase in body sway was found in the closed eyes condition compared to OE ones with and without headset (CE vs. OE, CE vs. HMD-OE), underlining the effect of visual deprivation, whereas no significant difference was observed between the HMD-CE and OE conditions and a significant decrease in HMD-CE compared to the CE condition, showing the sensory-proprioceptive effect of the HMD. Eventually, no significant differences in plantar pressure parameters were generally found in different conditions. Conclusions: These findings highlighted the specific effect of visual afferents differently from proprioceptive ones by headset use and the absence of the VR impact on postural stability, suggesting a possible role of virtual reality in standardizing instrumental postural exam.