Effect of Ankle Joint Flexion Angle on Lower Extremity Muscle Activity and Break Point Angle during Nordic Hamstring Exercises in Amateur Soccer Players

Purpose:The purpose of this study was to determine the effects of ankle dorsiflexion, neutral, and plantarflexion on lower extremity muscle activity and break point angle (BPA) during Nordic hamstring exercises.Methods: Twenty-four members of a college soccer club (age, 21.682.39years; height, 175.634.76cm; weight, 71.886.29 kg) were recruited to participate in the experiment, and all subjects were measured three times in triplicate for Nordic hamstrings at three different ankle angles with all subjects in one group.Surface electromyography equipment (miniDTS, Noraxon Inc.) was used to acquire 3 seconds of muscle activity data at the starting point (90) during exercise, and motion analysis software (Kinovea version 0.9.5, Kinovea) was used to collect kinematic data at the point where knee strike angular velocity exceeded 30/sec for BPA data acquisition. Results:The results of this study, lower extremity muscle activity was not significantly different in the three variants of Nordic hamstring exercises, but BPA was significantly lower in the dorsiflexion position (60.286.35)compared to the neutral position (65.326.35)and plantarflexion position (63.827.01)(p 0.001). Conclusion:These results suggest that the dorsi flexion position of the ankle during Nordic hamstring exercises allows the body to maintain the position for a longer period of time against eccentric forces in situations where the body is moving forward.This suggests that the ankle dorsi flexion position can be used as a position for effective Nordic hamstring exercises in amateur soccer players.