The Just Jump System offers the coach and sport scientist with a number of modes to measure a wide range of speed, reaction time, foot quickness, multi-directional shuttle runs, aglity runs and shuttles. The Explosive Leg Power Factor how is extremely useful in monitoring athlete performance in a variety of dynamic power based activities including track springint, volleyball and basketball.

Explosive Leg Power Factor (ELPF) is the air time divided by ground time, most easily measured by using the Just Jump Mat System using the “4 Jump Mode”. This mode measures the ability of the athlete to get out of the starting blocks i.e. reaction time. The athlete stands on the Just Jump Mat and jumps four times in succession as quickly and high as possible. The Just Jump System computes the average ground time, the average jump height and the explosive leg power. The les time on the ground and the higher the jump the greater the ELPF.

A good performance for ground time in this test is 0.20 to 0.23 seconds. A good performance would generate a Explosive Leg Power Factor greater than 2.50. A good performance of vertical jumping is to achieve a height greater than 20 inches or 50 centimetres.

The following table illustrates the ELPF parameter as a function of ground time and jump height: