Document Type



The purpose of this research was to evaluate the motion and time change by training aiming at shortening the slide step delivery time of baseball pitchers. Six collegiate baseball pitchers were participated in the experiment as participants. They performed three fastball pitches with full effort (both as fast and quick as possible) by slide step deliveries before (Pre) and after (Post) one-month training period. For the phase time, there were significant differences between Pre and Post in the Phase 1 and total. There were no significant differences in Phase 2 and Phase 3. The lift height of the knee of the stride leg showed no significant difference. Therefore, to shorten the time of stride phase without decrease the lift height of the knee of the stride leg is necessary to shorten the slide step delivery time.