Visual Biofeedback Improves Balance Control. Until It Doesn'T

PURPOSE: Visual feedback of one’s balance has potential to augment balance training. However, natural visual cues of the environment already provide robust stabilization, and therefore additional visual biofeedback may have little effect on body sway. We quantified the extent to which different types of visual feedback influence sway in a novel trunk balancing task. METHODS: Twelve healthy young adults sat on a motorized bench that tilted up and down in direct proportion to trunk sway. This paradigm greatly increases the difficulty of the balance task and requires subjects to rely on visual and vestibular systems. In each trial, participants were provided different types visual feedback through a rotating needle-gage display on a 15 by 20 cm computer monitor located 0.85 m in front of the participant. Trials lasted 100 s, were randomly ordered, and included direct feedback (needle rotated in proportion to body sway), inverted feedback (needle rotated in the opposite direction of sway), time delayed feedback (0.5 s), random feedback RF, eyes closed, and control (eyes open with screen off). Participants were informed “visual feedback might be helpful”. RESULTS: Direct feedback trials had a large and significant (p