INVESTIGATING THE EFFECTS OF FEEDBACK TIME DELAY IN HUMAN UPRIGHT STABILITY USING VIRTUAL REALITY

The study of human postural instability and its mechanism is critical for understanding the fall mechanics and the underlying factors engendering the instability in human postural balance. This is especially crucial given that the identification of these instabilities aid in the identification of fall risk, fall prevention strategies, and rehabilitation post-fall. In this study, we analyze the postural instability of upright human stance and the mechanisms responsible for the induction of this instability through artificial manipulation of the visual sensory feedback time through the application of virtual reality (VR). Previous studies have established the existence of instability via limit-cycle oscillations (LCOs) when the combination of neuromuscular gain and delay is excessive in a mathematical model, but experimental proof remains elusive. Through the manipulation of the visual sensory feedback in VR, we try to understand and evaluate specific neuromuscular mechanics, such as delay in feedback and its effects on muscle strength resulting in instability. Also, we try to observe the existence of compensating behavior in upright balance in subjects after the time of sustained delay.