Visual biofeedback has been widely used in training programs aimed at improving postural balance through the reduction of postural sway. However, studies have shown variability between individuals in their ability to reduce postural sway while using visual biofeedback, suggesting that some individuals may not rely heavily on visual cues to adjust their posture. An important question arising from these findings is whether individuals who rely on visual information differ from those who do not in their postural strategies when engaging in biofeedback tasks.

This study investigated the effect of visual contribution on muscle activity and postural sway in young adults while standing and using different visual biofeedback tasks.

Twenty participants performed four distinct postural tasks, each lasting sixty (60) seconds: (1) Eyes open (EO), as a control condition; (2) Eyes closed (EC); (3) center of pressure (CoP) biofeedback using 2 cm (3a) and 4 cm (3b) targets; and (4) wrist-controlled laser biofeedback. Electromyograms (EMG) were collected from the right tibialis anterior (TA) and medial gastrocnemius (MG), and CoP displacement was measured in the anterior-posterior (AP) and medial-lateral (ML) directions. The index, based on percentage difference of COP sway area [(EC area EO area)/(EC area+EO area) × 100] was used to determine the weight of visual information in postural control, dividing individuals into vision or non-visual. The Friedman test was used, followed by the post-hoc Wilcoxon test for pairwise comparisons between conditions, with a significance level of 5%.

Eight individuals were classified as visual, with a larger COP sway area in the EC than in the EO condition, while eleven (∼58%) were classified as non-visual. In the visual group and when considering CoP biofeedback, the RMS of TA activity increased when using 2 cm target (p = 0.047) in relation to EO, but without differences in CoP variability. In the non-visual group, there were no significant differences in muscle activity, but the SD of the AP CoP and CoP sway area decreased with the 2 cm and 4 cm targets when compared to EO (p < 0.05). For laser biofeedback, no differences in muscle activity were observed; however, the SD of the AP CoP increased during this biofeedback task compared to the EO condition, regardless of the visual group.

Postural adaptations to CoP biofeedback appear to depend on an individual&apos;s reliance on vision for postural control and the specific biofeedback protocol used. Visual-reliant individuals exhibit increased muscle activation when required to achieve a smaller reduction in CoP sway, as observed with the 2 cm target. In contrast, non-visual individuals reduce sway without additional muscular effort, regardless of the target size. Moreover, visual reliance did not influence postural strategy during laser biofeedback, as both groups demonstrated increased CoP sway variability under this condition.

These findings suggest that an individual’s reliance on vision for postural control should be considered when developing postural sway biofeedback protocols. Visual-reliant individuals may exhibit increased muscle activity in response to interventions aimed at enhancing postural stability or reducing postural sway.