BIOMECHANICS OF TAKEOFF TECHNIQUES IN MODIFIED JUMPING ACTIVITIES

Abstract

Introduction It is an accepted fact that a fast approach run is of significant importance for success in certain jumping events, such as the long jump and triple jump. This claim is supported, at least subjectively, by the observation that several of the world's greatest jumpers have also been world-class sprinters. Theoretically, maximum distance in jumping requires that the jumper attain not only a high H y at the takeoff point but also some V y as well, to ensure a sufficient flight time. Some horizontal jumpers intuitively place the takeoff leg well ahead of the center of gravity (C ofG) of the body and lean backwards in an effort to achieve a greater V y and thus a higher jump. Practical experience, however, dictates that "reaching" with the takeoff leg does not improve overall performance, perhaps because it causes a loss ofH y at the point of takeoff. It has been suggested that technique which emphasizes height in the jump might only increase the final V y at the expense of a greater reduction of H y (Tellez, 1980). That is, there might possibly be a trade off between vertical and horizontal velocities at takeoff.