The effect of choice reaction time task on pre-landing muscle timing in athletes with and without chronic ankle instability.

Introduction: The assessment of neuromuscular control strategies, especially investigating muscle timing and anticipation in muscles, is important to improve our knowledge about ankle instability and preliminary mechanisms of it. The goals of the present study were comparing reaction time, its components and anticipation time in athletes with and without chronic ankle instability after 'go signal' provided by visual choice reaction time task. Methods: Nineteen athletes [11 healthy athletes, 8 athletes with chronic ankle instability (CAI)] participated in this cross-sectional study with research laboratory setting. The subjects started forward jumping protocol while electromyographic data were recorded from their leg muscles included gastroc-soleus, peroneus longus, peroneus brevis, and tibialis anterior. Results: The results of two- way repeated measurement ANOVA revealed no significant difference in athletes with and without CAI except for pre-motor time and motor time of peroneus longus (interaction effects of the tested leg and tested group: P=0.032, F=5.434; and P=0.040, F=4.937, respectively). Conclusion: Some differences in timing of peroneus longus were seen, so it suggest that clinicians should pay extra attention to muscle timing and consider its recovery in rehabilitation protocols. Besides it seems that some of the non-significant results might be related to neuromuscular adaptation that occurred in field athletes. Further study with larger sample size was suggested. Level of evidence: 3b. [ABSTRACT FROM AUTHOR]