Impact of Chronic Ankle Instability on Jumping and Agility Performance in Athletes: A Comparative Study

Background The objective of this study was to assess functional performance in athletes with chronic ankle instability (CAI) and compare it with a healthy control group. Methods The study population comprised 16 athletes diagnosed with CAI and 16 matched, healthy athletes. Functional performance was evaluated using side jump test, 6-meter timed hop test, single-leg hop test, triple crossover hop test, lateral hop test, and countermovement jump. Additionally, agility tests including the 5-10-5 test and the acceleration-deceleration-acceleration (ADA) test were administered. Independent sample t-tests and Mann-Whitney U tests were used for intergroup comparisons, and effect sizes were calculated using Cohen's d. Results Athletes with CAI demonstrated significantly reduced performance in jumping and agility tests compared to the control group. Specifically, notable decreases were observed in vertical jump height, jump power, agility time, and lateral jump distance. However, no significant correlation was found between Cumberland Ankle Instability Tool (CAIT) scores and functional performance tests. Conclusion This study highlights the negative impact of CAI on functional performance, particularly in jumping and agility domains, among athletes. The findings emphasize the importance of incorporating exercise programs targeting functional performance into rehabilitation strategies for CAI. In clinical practice, combining subjective and objective measurements may aid in developing comprehensive rehabilitation plans for individuals with CAI. Clinical trials: The study was prospectively registered with ClinicalTrials.gov under the identifier NCT07171411 on September 6, 2025.