The effect of variable speed rotational visual-vestibular interference on human stance stability

This study investigated the effects of visual-vestibular interference on static standing balance during variable-speed rotational patterns. We employed a head-mounted display and a rotating platform to manipulate visual and vestibular perceptions respectively. Both devices operated on a sinusoidal variable speed pattern and were controlled to generate both congruent and incongruent sensory experiences. 30 subjects were assigned to either a short (5 min) or a long duration (20 min) group. Subjective dizziness was rated on a 0–10 scale and self-perceived movement was assessed. Center-of-pressure (COP) data were collected using a force platform before and after each intervention. The results indicated that: (1) 8 subjects failed to complete all the experiments. Incongruent interference induced significantly heightened dizziness and caused the majority of subjects (19/22) misjudged their rotational direction; (2) The 5-min interference did not cause significant changes in COP displacement or velocity, but frequency-domain analysis indicated subjects enhanced visual reliance and reduced proprioceptive weighting, reflecting a sensory reweighting strategy; (3) The 20-min incongruent interference significantly disrupted postural stability, manifested as comprehensive increases in total COP displacement, sway velocity and area, with effects markedly stronger than under congruent conditions. This study highlights the importance of visual information in postural control. Additionally, the sensory reweighting strategy appears insufficient compensate for the impacts of prolonged sensory interference.