Muscle timing in injured and non-injured leg of athletes with chronic ankle instability in response to a visual stimulus during forward jumping.

OBJECTIVE

The aim of this study was to investigate premotor time, motor time and reaction time of the injured and non-injured leg muscles of athletes with chronic ankle instability in response to a visual stimulus during forward jumping.

METHODS

Surface electromyography was performed on injured and non-injured leg of eight athletes with chronic ankle instability during forward jumping.

RESULTS

Results showed that premotor time of the peroneus longus was significantly longer in non-injured leg compared with injured leg (489.37 ± 220.22 ms vs. 306.46 ± 142.92 ms, P = 0.031); on the contrary, motor time of the peroneus longus was significantly shorter in non-injured leg compared with injured leg (569.04 ± 318.62 ms vs. 715.12 ± 328.72 ms, P = 0.022). No significant difference was noted in the timing of other calf muscles (P > 0.05).

CONCLUSION

According to the results of this study, rehabilitation protocols, regarding ankle instability, need to put greater emphasis on tasks that require proper timing of muscles and muscle re-education so that protocols could reduce residual symptoms after sprain and prevent recurrent sprains.