Biomechanics of 8-week Hand-held Extra Weight Jump Trainning To Junior High School Male Students

[[abstract]]Purpose ：The purpose of this study was to investigate the biomechanical difference between unloaded and loaded jumps of standing long jump, and to compare the difference between pre-test and post-test of 8-week loading jump training. Methods：Fifteen Junior High School Male Students participated the study, and they tried 5 different loads to find the optimal load. Vicon motion analysis system(10 cameras, 200Hz) and two Kistler force plates(1000 Hz) were used to collect the 3D kinematics and kinetic data of pre-test and post-test. All data were analysed using mixed design two-way ANOVA and Pearson product-moment correlation to test the selected variables at .05 significant level. Findings： (1) The optimal load of these students was 4 kg. (2) The loaded jump had greater jump distance (8.25 %) than no load jump in pre-test, and the jump distance was enhanced (17.96 %) in post-test than pre-test. (3) After 8-week training, the CM horizontal takeoff velocity, flight distance, landing distance, CM height between takeoff and landing, peak lower extremity angular velocity, GRFx, peak lower extremity torque, peak lower extremity power were significantly enhanced. Conclusions：After 8-week training, the participants enhanced the jumping distance, it indicated that training program worked.