Athletes with chronic ankle instability adopt protective landing strategies and exhibit reduced anterior talofibular ligament strain during dynamic inversion perturbations.

Abstract

Objectives: This study aimed to compare lower-limb landing kinematics and modeled anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) strains between athletes with and without chronic ankle instability (CAI) during a dynamic inversion-plantarflexion perturbation, and to determine whether altered landing strategies in athletes with CAI were associated with increased or reduced ligament strain.

Design: Cross-sectional study.

Methods: 55 athletes with CAI and 55 without CAI were recruited. Each participant performed a 30-cm drop landing on a simulated sprain apparatus. The unaffected limb was placed on a support pedal, while the affected limb landed on a tilt pedal that was set to 24° of inversion and 15° of plantarflexion to simulate the condition of lateral ankle sprains. Kinematic data were obtained using a 12-camera motion analysis system, and ATFL and CFL strains were calculated with a 3D rigid-body foot model. Independent sample t-tests and Pearson's correlations were used to analyze data.

Results: Athletes with CAI exhibited higher hip flexion (p < 0.001), hip abduction (p < 0.001), knee abduction (p = 0.043), ankle external rotation (p = 0.032), foot toe-out (p < 0.001) angles and lower ATFL strain (p = 0.002). ATFL strain was negatively correlated with ankle external rotation (r = -0.263, p = 0.006), and foot toe-out (r = -0.286, p = 0.002) angles.

Conclusions: Athletes with CAI adopt a protective landing strategy compared to those without CAI. This strategy was associated with reduction in ATFL strain, which may help mitigate the risk of lateral ankle sprain during challenging landings.