PURPOSE This study aimed to analyze the differences in center of pressure (COP) and sample entropy (SampEn) between the right and left supporting legs during a single-leg stance task involving vertically and horizontally moving visual stimuli tracking. The objective was to examine the directional processing of visual information and functional asymmetry of the feet in postural control, providing foundational data for balance training design. METHODS This study recruited 20 right-footed adult men (mean age = 26.84 ± 4.47 years) who scored >7 on the Waterloo Footedness Questionnaire-Revised. The participants performed a 30-second single-leg stance while tracking visual stimuli with their gaze under different directional conditions. RESULTS Significant differences were observed across gaze directions in all COP and SampEn variables, with the left–right condition yielding the highest values (p < .05). Regarding the supporting leg, a significant difference was observed only in SampEn values in the anteroposterior direction. Moreover, a significant interaction effect between gaze direction and supporting leg was noted in SampEn in the mediolateral direction. CONCLUSIONS These findings suggest that the right and left supporting legs use different postural control strategies. Specifically, the left supporting leg demonstrated a tendency to adopt more complex and adaptive control mechanisms under horizontal gaze shifts, indicating functional asymmetry in postural regulation.
