Changes in Peak Torque and Surface Electromyography after Dynamic Stretching

Abstract

[Purpose] To clarify the relationship between the constant velocity muscle force of the hip flexor muscle group and surface electromyography (EMG) due to the number of repetitions of dynamic stretching (DS). [Participants and Methods] Seven healthy males participated in this study. The DS performed in this study was hip flexion repetitions of 10, 20, 30, 40 and 50 times. The peak torque of hip flexion was measured before and after DS. EMG of the rectus femoris, tensor fasciae latae and adductor longus were recorded simultaneously with the peak torque measurement. [Results] The peak torque showed a significantly high value only after performing DS 20 times. Although the integrated EMG values and the median power frequency showed no difference between before and after DS, a scalogram showed brightness convergence. [Conclusion] The peak torque increased after DS was performed 20 times, and it was confirmed that muscular performance changed without changes in muscle activity.