Kinesiological Limits of Vertical Jump Performance

Abstract

The purpose of this study was to investigate the kinesiological factors (strength of the lower limbs, and kinematics and dynamics of the jump) which distinguish good jumpers from poor ones, and also those which distinguish better from worse trials within a single individual, in an attempt to understand the critical factors in vertical jump performance (VJP). Two separate experiments were carried out, both with normal, physically active male college students. For study #1, 52 subjects performed five maximal vertical jumps with arms akimbo. The best jump was used in the analysis. For study #2, ten subjects each performed 50 maximal vertical jumps with arms akimbo. Ground reaction forces and moments of force, as well as video data, were collected during the jumps. Subjects in study #1 also had their lower limb strength tested isometrically. A total of 35 potential predictor variables were calculated and ordered according to a theoretical model of vertical jumping. Multiple regression analysis techniques were used to develop a series of statistical models for the prediction of VJP. At the whole-body level of analysis, the best predictors were peak and average mechanical power. Together with body weight, time of propulsion, and amplitude of the movement, the models were able to account for 88% of VJP variation between subjects and from 48 and 83% of VJP variation within subjects. However, the information that predictors in these whole-body models provide about muscle actions during the jump is very limited. At the segmental level, the best models accounted for 60% of between-subjects variation and from 34 to 51% of within-subjects variation in VJP. Muscular strength was relevant, but not as much as joint torques or joint powers during the execution of the jump. The latter were relevant predictors even within subjects. Contrary to the expectations, a proximal-to-distal sequence of joint reversals was associated with lower jumps, when compared with a HIP-ANKLE-KNEE sequence. Other coordination variables were not related to VJP.