Real-time visual feedback on dynamic postural stability modulates performance and strategy

Lower limb injuries are prevalent in sports and frequently recur, with impaired dynamic postural stability identified as an important risk factor. Real-time visual feedback has shown potential to improve postural stability, yet the relative effectiveness of different feedback types remains unclear. This study investigated the effects of four types of real-time visual feedback on dynamic postural stability during a single-leg perturbation task using a between-subject design. Eighty-nine healthy participants performed 192 mediolateral perturbations, to evoke and then measure balance responses, divided across a warming-up, feedback, and retention condition. Participants were assigned to one of five groups, receiving feedback on center of pressure speed (CoPS), time-to-stability (TTS), vertical force deviation (FYdev), trunk angular velocity (TAV), or no feedback (control). Outcome measures were these four measures and the angular velocities of the arms (AAV) and swing leg (SAV). For each outcome, ANCOVAs with warming-up performance as covariate were followed by pairwise comparisons with the control group. FYdev and TAV feedback improved their targeted outcome measure (both p < 0.01), whereas CoPS and TTS feedback did not. All four feedback types reduced SAV (p < 0.05), FYdev feedback additionally reduced CoPS and TTS (p < 0.05), and CoPS and TAV feedback both reduced TAV and AAV (p < 0.05), indicating reduced reliance on the counter-rotation strategy. Only TAV feedback showed retained effects once feedback was removed, with lower TTS, TAV, AAV and SAV than the control group (p < 0.05). Group by baseline interactions indicated that participants with poorer warming-up performance improved most during TTS and TAV feedback (p < 0.01). These findings indicate that real-time visual feedback enhances dynamic postural stability, mainly through general rather than measure-specific adaptations. Trunk angular velocity feedback most consistently modified the counter-rotation strategy and was the only feedback type with retained effects within the same session in the absence of feedback.