The effects of visual biofeedback and visual biofeedback scale size on single limb balance

Background: Controlling postural sway relies on the assessment and integration of external sensory stimuli by the central nervous system. When there is a loss of one or more of the sensory stimuli, there is often a decrease in balance performance. Visual biofeedback (VBF) has become a popular method to improve balance because of the supplementation to natural visual information with visual cues of the center of pressure. It is also possible to improve balance even further by increasing the scale of VBF. The aim of this investigation was to determine the effects of VBF and increasing VBF scale on single-limb balance in healthy adults. Methods: Twenty healthy young adults were recruited. Participants underwent 24, 20-s single limb balance trials on both the right and the left leg. These trials were collected under 4 conditions: 1) eyes-open (EO) with no VBF, 2) EO with 1:1 scale VBF, 3) EO with 2:1 scale VBF, 4) EO with 5:1 scale VBF. Force plate outcomes included resultant, anterior-posterior, and medial-lateral Sway. A two-way repeated measures ANOVA was performed and a Bonferonni post-hoc test was used to determine the effects of VBF and VBF scale size on balance. Results: Differences were noted in AP Sway and Resultant Sway when VBF was present and the scale size was increased (p < 0.05). Conclusion: Providing VBF decreases Sway in single-limb stance for young healthy adults, especially when the scale was increased beyond 1:1 VBF. These results may be clinically applicable for balance rehabilitation and training.