Effect of optokinetic virtual reality scenes on a sitting-to-stand movement

Visual perception plays a role in balance control while performing a sit-to-stand movement (STS). The dynamic virtual environment could reduce effective neuromuscular regulation and instability. Nevertheless, virtual reality (VR) on the STS movement was not explored in any research.This study's aim was to investigate the effect of the VR of an optokinetic drum on the STS movement by using optokinetic drum VR scenes.This study used a repeated measurement research design. Ninety healthy subjects aged 18-23 years with no experience in virtual reality were recruited. Each participant was asked to stand as quickly as possible from a height-adjustable chair three times under five conditions: with eyes-open (EO), eyes-closed (EC), and three VR scenes: a limited field view of an optokinetic scene, a black and white striped scene, moving in horizontal direction (VRhori), vertical direction (VRvert), and roll (VRroll). VR scenes were generated using a mobile phone in a head-mounted display. The rising index (the upward force produced by the legs as a proportion of body weight), sway velocity, and weight transfer time were measured using a NeuroCom Balance Master.Only VRvert condition significantly reduced weight transfer time as compared to EO and the other two VR conditions. All three VR scenes significantly reduced the rising index as compared to EO. VRvert condition significantly increased sway velocity as compared to all conditions.These findings suggest that optokinetic environment scenes in virtual reality could be used as an alternative method to increase the challenge of maintaining the balance during STS.