Landing adaptations in individuals with chronic ankle instability.

Background: This study compared the landing strategy on a flip platform between individuals with and without chronic ankle instability (CAI), to provide a biomechanical basis for reducing re-injury risk. Methods: 55 participants with CAI and 55 without CAI were recruited. Each participant landed on a simulated sprain apparatus with the unaffected limb placed on a support platform and the affected limb on a flip platform. Kinematic data were captured using a 12-camera motion analysis system. Independent-samples t-tests were used for statistical analysis. Results: Individuals with CAI exhibited lower maximum ankle plantarflexion angle [CAI: 27.1° ± 8.1° non-chronic ankle instability (non-CAI): 31.5° ± 8.2°, p = 0.010] and higher maximum hip flexion (CAI: 49.2° ± 12.1°, non-CAI: 41.5° ± 14.2°, p = 0.004), maximum hip abduction (CAI: 14.7° ± 4.4°, non-CAI: 12.0° ± 5.5°, p = 0.009), maximum knee abduction (CAI: 8.8° ± 4.5°, non-CAI: 5.0° ± 3.3°, p < 0.001), and maximum foot toe-out (CAI: 18.7° ± 8.6°, non-CAI: 14.3° ± 4.5°, p = 0.002) angles. Conclusion: Individuals with CAI adopt a cautious landing strategy compared to those without CAI.