Kinematic Analysis of Take off Technique on the Performance of the Fosbury Flop

Abstract

The high jump is one of the most technical and complex event of the athletics. Top high jumper's in the world use one of the versions of Fosbury Flop technique , this proved the most efficient so far. This technique comprises the preparation for the touchdown, take off, the flight phase , bar clearance and landing. It is not easy to learn and perform, since it requires some special skills. Its mechanical and dynamic analysis reveals movements of an exceptional difficulty that cannot be so easily assimilated by most jumpers. Certain time of execution (particularly those made over the bar) requires a psycho motor control and an extreme sensibility that can't be easily reached by everyone. Thirteen male national high jumpers were selected for this study and get videotaped with three high speed video cameras during their competitive performance in the men's high jump final during the 52nd National open athletics championship in outdoor with the informed consent of the athletes. In this research we used three Panasonic-AG-DVX-102B, F11 sensitivity, high image quality, camcorders, Quintic Biomechanics v21 motion analysis software. I. Introduction To clear a high jump bar, it is necessary to drive the center of mass (COM) of the athlete as high as possible. It is also necessary to move the body in the air in a way that will allow the athlete to clear a bar set as close as possible to the peak height reached by the COM. For a given peak height reached by the COM lowering some parts of the body allows other parts to go higher. This was the mechanical principle that has improved the effectiveness of the bar clearance over the years. If a high jumper remains in a straight vertical position after taking off from the ground, the height of the bar that the feet will be able to clear will be far below the peak height of the COM. The simplest improvement over this was a technique in which the athlete flexes at the hips and knees to adopt a squatting position at the peak of the jump. We could call this the legs-up technique. Since the peak height of the COM can't be changed after the athlete leaves the ground, the lifting of the legs is accompanied by a lowering of the trunk. This technique greatly increases the height of the bar that has to be cleared. The major purpose of this study was to investigate the take-off motion at the end of the last stride and identify the characteristics for optimum performance executed by Fosbury-flop jumpers, using 2-dimensional videography. The best jumps of thirteen male high jumpers were filmed at an official track meet by two high- speed cameras. The results suggested that to lower the center of gravity during the touchdown, Fosbury flop jumpers' takeoff leg was planted ahead of the torso by leaning the body backward. II. Methodology Selection of Subjects: Thirteen male national high jumpers were selected for this study and get videotaped with three high speed video cameras during their competitive performance in the men's high jump final during the 52nd National open athletics championship in outdoor with the informed consent of the athletes. Tools and equipment's: