QUANTIFICATION OF DROP JUMPS FOR TRAINING IMPLICATION

Peak vertical ground reaction force (F1peak), duration on force plate, flight time, and the eccentric loading rate (ELR) were examined during seven drop jumps (DJ) from 22.9 to 68.6 cm and a counter movement jump (CMJ). Thirty-four volunteers performed 16 jumps (14 DJs and 2 CMJs). Subjects were instructed to drop without changing the vertical component of the center of mass. They jumped maximally each jump using any technique and a rest period of 3+min between each jump was implemented. The data were gathered via force plate. Results indicated a significant F1peak difference between trials. There was a significant flight time difference between CMJ and DJs in a given trial, but no differences between DJs in a given trial. No significant differences were present for time spent on the plate between jumps, however; the ELR was different for DJs at the extremes.