THE KINEMATIC DIFFERENCES of THREE TYPES of CROUCHED POSITIONS during A SPRINT START

This study identifies the optimal crouched starting positions (elongated, medium, or bunched) from push-off to the first two steps. Seven elite sprinters were recruited as participants in this study (aged: 21±2 years). A high-speed camera (250Hz) was used to collect motion-based images on a sagittal plane. Kwon3D (software) was used to analyze the center of mass (COM) movement, step length, foot linear velocity, take-off angle, and trunk angle. Participants were tested in a 60m sprint for bunched, medium, and elongated starting positions. A one-way analysis of variance (ANOVA) (α=0.05) with repeated measures was performed to determine the difference in kinematics in the three crouched starting positions. The LSD comparison was applied to examine differences among pairs of means. Our results indicated that the medium starting position demonstrated a greater first step length and foot linear velocity when compared to the bunched starting position. In the first step toe-off, a lower COM vertical velocity was observed in the medium starting position when compared with the elongated starting position. This study concluded that the medium starting position was the ideal starting position.