Dynamic postural stability and ankle strength in female dancers with chronic ankle instability, healthy dancers, and healthy non-dancers

This study aimed to determine ankle strength, dynamic postural stability, and their relationship in female dancers with chronic ankle instability (CAI) to provide insights into more effective rehabilitation strategies for this population. Cross-sectional design. Laboratory. Each group comprised 14 female participants: dancers with CAI, healthy dancers, and healthy non-dancers. Dynamic postural stability was assessed by calculating the Postural Stability Index from ground reaction forces recorded during a single-leg hop. Ankle inversion and eversion strength were measured as isometric peak torque and as concentric and eccentric peak torques at angular velocities of 30°/s and 120°/s (Nm/kg). Female dancers with CAI showed no significant differences in dynamic postural stability or ankle strength, and no correlation between them, compared with healthy dancers and healthy non-dancers. Healthy dancers exhibited a lower anteroposterior stability index (APSI) than healthy non-dancers (p = 0.013). Additionally, among healthy dancers, concentric and eccentric ankle eversion strength measures were negatively correlated with APSI (p < 0.05). These findings suggest that dynamic postural stability and ankle strength reflect distinct functional dimensions in female dancers with CAI, and that both should therefore be assessed and addressed with individualized interventions during rehabilitation.