The Relation between Block Spacing and Forces Applied to Starting Blocks by a Sprinter

Abstract

Sprinters adjust the arrangement of their starting blocks prior to a race, but there is no clear standard for arranging the blocks. It is unclear at present how the arrangement changes the forces applied to the blocks and consequently affects performance coming off them. The purpose of this study was to investigate the effects of the arrangement of the starting blocks on the forces applied to them. Forces applied by a sprinter to the front and the rear starting block as well as to the ground on the first step were measured using three force platforms for 18 different arrangements of block spacing. The results indicated that the amount of the impulse applied in starting posture to both the front and rear starting blocks changed little between the 18 arrangements. Likewise, no substantial change occurred in the forces applied to the ground on the first step. However, as the distance between the front and rear blocks changed, the ratio of the impulse applied to the front and rear blocks changed: as the block spacing was increased, the impulse applied to the front block during starting posture decreased while that at the rear block increased. In addition, changing the distance from the starting line to the front block influenced the relation between the block spacing distance and the forces applied to the two starting blocks.