Sprinting is an athletic event, where in a relatively short distance is covered in the least possible time. It is one of the eye-catchers of all track events, for its brevity and worldwide audience. The athletes to have clocked the least time in completing a 100 metre sprint are Usain Bolt from Jamaica (9.58 seconds) and Florence Griffith-Joyner from The United States of America, (10.49 seconds) in the male and female category respectively. (IAAF, 2015) In sprinting, the initial velocity of the sprinter is much lower than the finishing velocity. The transition from the resting position to fast running is what determines the time taken to complete the sprinting activity. For this, a perfect sprint-start is important, to reduce the transition time. There are three phases to the sprint start; “on your marks”, “set” and “go.” (Drew Harrison, 2005) In response to the “on your marks” command, the athlete’s hands and feet are placed on the ground, and the knees touch the ground. On hearing the “set” command, the athlete extends the knee of the leg in the rear, thus elevating the body’s centre of gravity, hands and feet still on ground. In the “go” phase, the athlete lifts the hands of the ground, and propels his body forward, to begin his sprint. In international sprinting events, the athlete usually adapts a crouched stance for sprint start. (IAAF, 2015) The starting crouch might be of three types, depending on the relative distance of the back foot with respect to the front foot. This distance is commonly referred to as “interblock spacing”, i.e. the distance between the two starting blocks of the athlete. There are three types of sprint start.
As the proverbial saying goes “well begun is half done”, an effective sprint start reduces the time taken by the athlete to cover the sprinting distance. (Bezodis, 2009) So, which of the three sprint start techniques more effective in producing greater impulse? Applying the Newton’s Second Law of Motion, and the Impulse momentum relationship, it can be derived that the impulse of force is equal to the change in momentum that it produces. The change in momentum is the change from the initial to the final velocity of the athlete during the sprint (Warden, 2003) states that the greater the impulse of force produced by the athlete, greater the velocity, thus lesser the time taken to finish the sprint. The need for this study is to make the sports students aware of the difference in the efficacy of the different sprint start techniques, and to let them decide on the most effective technique of their choice. Two techniques – The bunch technique and the medium technique were taken up for the study. The Initial and final stride length of the athletes was taken as the parameter for assessing the technique’s efficacy, in both male and female students.
The objective of this study is to determine the influence of the type of sprint start on the stride length of a sprinter.
Research hypothesis - “There is a significant improvement in stride length in medium start technique when compared to bunch start technique.”