A biomechanical assessment of fajin mechanisms in martial arts

Background & Study Aim: As a martial arts technique, fajin (“exerting strength”) is a reasonable and efficient method of utilizing muscle strength. The purpose of this study was to explore fajin movement mechanisms in terms of muscle activation. Material & Methods: A three-dimensional motion analysis system, force plates, and a wireless electromyography system were used to simultaneously collect kinematics, kinetics, and muscle activation from eight martial arts trainees who were familiar with fajin techniques. Statistical analysis was performed using Kendall’s coefficient of concordance at a significance level of α=0.05. Results: The results revealed that the maximum joint angular velocities, maximum joint angles, initiation of muscle activations, and peak muscle activations occurred in a fixed sequence. Conclusions: The fajin motor pattern is initiated by a push from the rear foot, which produces a ground reaction force and moves the center of gravity forward. All of the joint operations and muscle activation timings occurred in a fixed sequence in this study.