Countermovement Jump Height and Force-Time Variables

Do you use the Counter Movement Jump to measure better outcomes with your clients❓❓❓🧐 The countermovement jump (CMJ) is a simple, practical, valid, and very reliable measure of lower-body power. As a consequence, it is no surprise that this has become a cornerstone test for many strength and conditioning coaches and sports scientists. The CMJ is the most reliable measure of lower-body power compared to other jump tests. Furthermore, the CMJ has been shown to have relationships and may be a useful alternative to sprint performance, 1RM maximal strength, and explosive-strength tests.

Laffaye, G et al conducted a study to assess the eccentric rate of force development, the concentric peak force, and selected time variables on vertical performance during countermovement jump as well as looking at gender and differences in sporting performance.

3 main applications for practice were found.
The first is that a valid method to increase vertical performance or jump height is to increase one of either Peak Force, Eccentric Peak Rate Of Force Development as can be measured on AxIT’s Stomp-IT.

The second practical application is highlighted by the link between the time ratios on the force variables. Shortening the eccentric time of the jump without changing the total time, increases the values of the force variables and the performance as well. This implies that advice could be given during jumping tasks (drop jumping, CMJs) to decrease the eccentric time to increase performance.
Finally, the use of biofeedback devices such as Stomp-IT for jumping could be a good and rational way to increase the stretch-shortening cycle to become more explosive.
Also, it should be noted, sporting requirements have to be taken into account in an athletes training program. These findings reveal a time-prevailing profile for basketball and volleyball players and a force-prevailing profile for football and baseball players. Consequently, trainers should focus on the need to adapt jumping/plyometric technique in indoor jumping team sports, whereas as a greater focus is required to increase explosive force for dynamic outdoor sports such as football and baseball.