Impaired postural control following unanticipated single-leg landings in female soccer players with chronic ankle instability

This study investigated postural control following unanticipated single-leg landings in female soccer players with and without chronic ankle instability (CAI). Eighteen female soccer players, including 10 CAI and 8 healthy controls, participated in the study. They completed three successful 20-second single-leg stances following an unanticipated jump landing. Angular variations of the rearfoot, midfoot, and forefoot in the frontal and sagittal planes, as well as center of pressure (COP) data including total trajectory length, mean velocity, range, and time-to-boundary (TTB) in both the medial-lateral (ML) and anterior-posterior (AP) directions were collected during the single-leg stance task. The CAI group demonstrated significantly greater midfoot angular variation (0-5 s: p = 0.043; 5-20 s: p = 0.017), higher COP ML velocity (p = 0.002), and a longer COP trajectory length (p = 0.021). The mean of TTB minima in the ML direction was also significantly lower in the CAI group (0-5 s: p = 0.018; 5-20 s: p = 0.035). These findings suggest that female soccer players with CAI demonstrated impaired postural control following unanticipated landings, likely due to sensorimotor deficits. Incorporating spatiotemporal measures such as TTB may improve postural control assessments in individuals with CAI.