Comparison of the dynamics of the swimming grab start, squat jump, and countermovement jump of the lower extremity.

[[abstract]]The purpose of this study was to compare the dynamics characteristics of different jumps including the swimming grab start, squat jump, and countermovement jump. The subjects, who have over ten years experiences in swimming grab starts. One Peak-Performance high-speed video camera operating at 120 Hz and one Kistler force plate were synchronized to collect the data. A mathematical model of inverse dynamics was used to calculate net muscle joint moment and power. The results indicated that the grab start had a more complicated pattern of net muscle joint moment and power than other jumps. Based on the results of this study, it has been suggested that coaches should focus on the key points of grab start dynamics characteristics when instructing and training