Combining three-dimensional ankle exercises with short-foot training improves proprioception and dynamic balance in female karatekas with flatfoot: A randomized controlled trial.

OBJECTIVE: This study aimed to assess the effectiveness of a comprehensive training protocol including three-dimensional ankle exercise combined with short-foot exercise (SF-3DAE), compared to short-foot exercise (SFE) alone, in improving navicular drop, ankle proprioception, and dynamic balance in female karate athletes with flatfoot. DESIGN: Randomized controlled trial. SETTING: Rehabilitation laboratory. PARTICIPANTS: Thirty-four female karate athletes with flatfoot (mean age 20.79 ± 2.72 years) were randomized to SF-3DAE (n = 17) or SFE (n = 17). MAIN OUTCOME MEASURES: Navicular drop (Brody method), ankle proprioception (angle reproduction error), and dynamic balance (Y-Balance test). RESULTS: Group × time interactions were significant for all outcomes, with greater improvement in the SF-3DAE group for navicular drop (P = 0.001), proprioception (P < 0.001), and dynamic balance (P < 0.001). In the SF-3DAE group, navicular drop decreased by 2.24 mm, proprioception error by 3°, and total Y-Balance reach increased by 17.49 percentage points of leg length; corresponding changes in the SFE group were 1.16 mm, 1.59°, and 7.82 percentage points (P < 0.001). An individual-level responder analysis showed that most participants in both groups achieved reliable improvement in navicular drop, proprioception, and anterior/total balance, whereas the added benefit of SF-3DAE was concentrated in posteromedial and posterolateral balance, where responder rates were markedly higher than in the SFE group. CONCLUSION: Adding 3DAE to SFE produced greater improvements in foot posture, proprioception, and dynamic balance than SFE alone, with the clearest advantage in multidirectional balance, a pattern consistent with the greater peroneus longus and evertor recruitment associated with the diagonal movement patterns of 3DAE. Because the SF-3DAE group also received a greater volume of supervised exercise, this contribution cannot be fully separated from a general training-volume effect. Whether these improvements translate into enhanced athletic performance or reduced injury risk was not assessed and requires further study. TRIAL REGISTRATION: XXX (registered 12/28/2022).