Abstract des Autors

Performance in vertical jumps is dependent on the work done by the vertical component of the ground reaction forces during the upward movement of a subject's centre of mass. This study investigated whether the pattern of ground reaction forces, movement amplitudes, and force magnitudes used in vertical jumps from a static start (SJs) may enable attainment of peak kinetic energy of vertical translation equivalent to that attained in jumps performed with a preliminary counter movement (CMJs). Unlike many other studies of vertical jumps there were no constraints on movement amplitude used by the subjects to perform either type of jump. Thus, subjects had the opportunity to use a combination of force patterns, movement amplitude, and force magnitudes which maximised performance in each type of jump. Seven of the 17 subjects attained greater peak kinetic energy in the CMJs than the SJs. For six of the subjects there was very little difference in the peak kinetic energy despite differences in the pattern of forces, movement amplitudes and force magnitudes between the jump types. Four of the sujects attained greater peak kinetic energy in the SJs than CMJs. Of these, three achieved an enhanced performance by using an increased movement amplitude compared to the CMJs while the fourth achieved enhanced performance mainly by attaining greater forces in the SJs. Verf.-Referat