In track and field athletics, sprint races cover a range of distances from 60m up to 400m. Under the International Amateur Athletic Federation (IAAF) rules such races start from a crouched position in blocks. There are three main types of crouched positions: the bullet, the medium and the elongated positions (Hay, 1993). A crouched start is more effective than a standing start as it places the sprinter in a position to move the centre of gravity rapidly well ahead of the feet and thus the runner must accelerate very quickly or else fall (Adrian & Cooper, 1995). The start, however, must not be thought of as a separate part of the whole race. It is an integral part of the total race and consequently is not distinct from the entire sprinting event.