01/22/2026
A drop jump test is intended to measure an athlete’s reactive strength - the ability to utilize a fast stretch-shortening cycle (SSC). In other words, it measures the ability to effectively transition from eccentric to concentric contractions with minimal loss of energy in the amortization phase (ground contact). In order to do this test properly, the athlete should be achieving the same jump height from their standard countermovement jump (CMJ), while completing the test with a ground contact time (GCT) of 250ms or less. If the athlete is unable to achieve both of those metrics, it is likely the drop jump box height is too high for the athlete’s current abilities. Once the ground contact time exceeds 250 ms, it is no longer considered a fast SSC.
The first video is gathering jump height from a max CMJ test.
Then we performed a drop jump from 8” box height where the athlete is able to maintain his jump height while also having a GCT of 240ms which is faster than the goal of 250ms.
The final video is trialing a 12” box height, but he was unable to maintain either his jump height or a GCT of sub 250ms. This would indicate that this box height is too high for the athlete to still utilize a short duration SSC.
The popularized default box height for a drop jump test is 12” (31cm), however this is often unrealistic for many patients to maintain both jump height and
