Protective Reflexes of the Peroneal Longus Muscle in Response to Sudden Inversion Movement in Badminton Athletes and Sedentary Persons

Purpose: The objective of this study was to investigate the mechanism of ankle protection reflex and to compare the reflexive differences between person with and without receiving ankle proprioceptive exercise training. Method: Twenty-two subjects voluntarily participated in this study. Subjects were categorized into two groups. Group one was the exercise group in which all subjects received at least six weeks of ankle proprioceptive exercise. Group two was the non-exercise group in which all subjects were exercise less than one hour a week. A self-designed foot sudden inversion plate was used. EMG activity of common peroneal longus (CPL) muscle was investigated when the subject sustained an unexpected sudden ankle inversion movement. Ankle motion range and EMG activities were simultaneously collected at a sampling rate of 1000 Hz. Results: The results showed that subjects in exercise group had less ankle inversion angle (16.0±9.8°) than that of subjects in non-exercise group (20.0±7.60). However, this difference did not reach the significant level (p＞0.05). The CPL’s reaction time during ankle sudden inversion in the exercise group had significantly shorter reaction time (56.5±11.6 msec) thanthat of the non-exercise group (68.8±9.7 msec). Conclusion: Our results support the theory that ankle protection reflex can be improved through ankle proprioceptive exercise.