This study investigated how chronic ankle instability (CAI) affects functional performance in athletes compared with healthy controls. CAI is a condition that develops after repeated ankle sprains, leading to ongoing "giving way" episodes, pain, and reduced stability. A total of 32 athletes participated: 16 with CAI and 16 healthy, age- and sport-matched controls. Participants performed a series of sport-specific functional performance tests, including single-leg hop tests, triple crossover hop, lateral hop, 6-meter timed hop, side jump, countermovement jump (CMJ), the 5-10-5 agility test, and the acceleration-deceleration-acceleration (ADA) test. The Deepsport AI program was used for precise measurement of jumping and agility parameters. Results showed that athletes with CAI had significantly lower jump height and power, reduced hop distances, and slower times in agility and hopping tests compared to controls. These findings suggest that CAI negatively impacts performance in explosive and multidirectional movements, which are essential in sports such as basketball, volleyball, and soccer. No strong correlation was found between CAIT (Cumberland Ankle Instability Tool) scores and objective performance outcomes, suggesting that subjective reports alone may not fully capture functional deficits. This study highlights the importance of using both subjective questionnaires and objective tests to evaluate ankle instability in athletes. It also supports the need for rehabilitation programs that include not only balance and proprioception training but also specific exercises to improve jumping, agility, and multidirectional performance.
Chronic ankle instability (CAI) is a frequent consequence of lateral ankle sprains, affecting up to 74% of athletes with previous ankle injuries. It is characterized by recurrent sprains, repeated "giving way" episodes, reduced function, and impaired performance. While CAI has been extensively studied in relation to balance and proprioception, its direct effects on sport-specific performance metrics such as jumping and agility remain less clear. In this cross-sectional case-control study, 32 athletes were enrolled: 16 athletes with CAI and 16 matched healthy athletes with no history of ankle instability. The CAI group was diagnosed using International Ankle Consortium (IAC) criteria (history of ≥1 lateral ankle sprain ≥12 months prior, ≥2 giving way episodes in the past 6 months, CAIT score ≤24, ≥5 years of sports participation). Controls had CAIT scores ≥25 and no ankle injury history. The testing battery included: Hop tests: single-leg hop, 6-meter timed hop, triple crossover hop, and lateral hop. Agility tests: 5-10-5 pro-agility shuttle and acceleration-deceleration-acceleration (ADA) test. Jump tests: countermovement jump (height, flight time, power) and side jump test. Measurements were supported by the Deepsport AI program for objective performance analysis.
Study Type
OBSERVATIONAL
Enrollment
32
Participants performed a standardized battery of sport-specific performance tests during a single laboratory session, including: Countermovement Jump (height, power, flight time) 5-10-5 Pro-Agility Shuttle Test Acceleration-Deceleration-Acceleration (ADA) Test Side Jump Test 6-Meter Timed Hop Test Single-Leg Hop Test Triple Crossover Hop Test Lateral Hop Test Performance was assessed using the Deepsport AI program and standard timing/distance protocols. Results compared between CAI and control cohorts.
University of Health Sciences
Ankara, Etlik, Turkey (Türkiye)
Countermovement Jump - Jump Height
Jump height (cm) measured during countermovement jump using Deepsport AI. Best of 3 trials recorded.
Time frame: Single laboratory session (~60 minutes)
Countermovement Jump - Flight Time
Flight time (s) measured during countermovement jump with Deepsport AI. Best of 3 trials recorded.
Time frame: Single laboratory session
Countermovement Jump - Power Output
Power output (W) calculated from CMJ using Deepsport AI (jump force-time algorithm). Best of 3 trials recorded.
Time frame: Single laboratory session
5-10-5 Pro-Agility Shuttle - Completion Time
Total completion time (s) for the 5-10-5 shuttle test, measured with electronic timing gates. Best of 2 trials recorded.
Time frame: Single session
Acceleration-Deceleration-Acceleration (ADA) - Total Time
Total sprint time (s) across 10 m acceleration, 5 m deceleration, and 10 m re-acceleration, measured with Deepsport AI.
Time frame: Single session
Side Jump Test - Completion Time
Time (s) to complete 10 consecutive lateral single-leg jumps across a line. Best attempt recorded.
Time frame: Single session
6-Meter Timed Hop - Completion Time
Time (s) to hop forward 6 meters on one leg, measured with stopwatch. Best of 3 trials recorded.
Time frame: Single session
Single-Leg Hop - Completion Time
Time (s) to hop forward 6 meters on one leg. Best of 3 attempts recorded.
Time frame: Single session
Triple Crossover Hop - Distance
Distance (m) covered in 3 consecutive crossover hops over a 15 cm line. Best of 3 trials recorded.
Time frame: Single session
Lateral Hop Test - Distance
Distance (m) covered in 3 consecutive lateral hops on one leg. Best of 3 attempts recorded.
Time frame: Single session
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