Increase in Jumping Height Associated with Maximal Effort Vertical Depth Jumps

Abstract In order to assess if there existed a statistically significant increase in jumping performance when dropping from different dropping heights, 32 young males, ages 19 to 26, performed a series of maximal effort vertical jumps after dropping from a variable height step onto a force plate. Five trials were performed from each of eight heights of 0, 25, 35, 45, 55, 65, 75, and 85 cm. Subjects were classified into two groups, volleyball players (n = 12) and nonjumpers (n = 20) based upon their current physical activity. Measures of the rise of the center of mass, vertical velocity at takeoff, total time on the platform, and total vertical impulse were obtained. A two-factor analysis of variance with repeated measures across dropping heights was used to assess if there was a difference in the performance of the depth jump between volleyball players and physical education students. There was a significant grouping effect. The volleyball players jumped higher than the physical education students in all conditions. The countermovement jumps (zero height) were significantly greater than any depth jump for both groups. No significant differences in the height of the vertical jump within either group was evident when jumping after a prior drop. There were no differences in the results if the best or average performance at each drop height were analyzed. The data from other published reports on this topic appear consistent with the concept that there is no difference between the performance when dropping from difference heights.