Longer reaction time of the fibularis longus muscle and reduced postural control in basketball players with functional ankle instability: A pilot study

Background: Motor control evaluation in subjects with functional ankle instability is questionable when both ankles of the same subject are compared (affected vs non-affected). Objective: To compare the postural control and reaction time of ankle muscles among: basketball players with FAI (instability group), basketball players without FAI (non-instability group) and healthy non-basketball-playing participants (control group). Design: Case-control study. Setting: Laboratory. Participants: Instability (n=10), non-instability (n=10), and control groups (n=11). Main outcome measures: Centre of pressure variables (area, velocity and sway) were measured with a force platform. Reaction time of ankle muscles was measured via electromyography. Results: A one-way ANOVA demonstrated that there were significant differences between the instability and non-instability groups in the fibularis longus (p<0.001), fibularis brevis (p=0.031) and tibialis anterior (p=0.049) muscles. Repeated-measures ANOVA and post hoc analysis determined significant differences for the area between the instability and non-instability groups (p=0.001). Conclusion: Basketball players with FAI have reduced postural control and longer reaction time of the fibularis and tibialis anterior muscles.