INTRASUBJECT VARIABILITY OF THE KINEMATICS OF THE VERTICAL JUMP

The variability of the kinematics of the vertical jump was studied in a sample of eight young adults. Six maximal effort vertical jumps from each subject were analyzed with the Peak Motus 2D videography (60 Hz) system. Kinematics of a seven segment model were calculated from the initiation of downward movement to five frames after take-oft. The intrasubject variability was usually small but depended on the kinematic variable of interest. Discrete angular kinematic variables of key events had mean standard deviations between 2.7 and 6.5 degrees. Most displacement and velocity variables had coefficients of variation between 1 and 1 0 percent. These vertical jumpers used consistent movement patterns so single jumps would be representative of normative performance