Pain-stratified differences in lower-limb mechanics and neuromuscular activation during single-leg drop landing in male athletes with chronic ankle instability.

Abstract

Objectives To compare mechanical and neuromuscular strategies between high- and low-pain subgroups of male athletes with chronic ankle instability (CAI) during single-leg drop landing. Design Cross-sectional study. Setting Biomechanics laboratory. Participants Eighty-four male Tier 2-3 athletes, stratified into high-pain CAI (n = 28), low-pain CAI (n = 28), and healthy control (n = 28) groups. Main outcome measures Lower-limb kinematics, impact loading, joint moments, eccentric work and energy contributions, surface electromyographic root mean square amplitude, and co-contraction index. Results Significant group effects were observed for kinematic outcomes (p ≤ 0.042; η p 2 = 0.075-0.384), joint kinetics and energetics (p ≤ 0.042; η p 2 = 0.075-0.561), and neuromuscular outcomes (p = 0.005-0.017; η p 2 = 0.096-0.124). The high-pain CAI group exhibited lower ankle plantarflexor moment than both comparison groups (both p p 2 = 0.032-0.058). Conclusions Pain-defined CAI subgroups differed in interjoint load sharing and selected neuromuscular measures despite comparable external impact loading.