The 6 Phases of the Countermovement Jump (CMJ)

Force plates can feel overwhelming at first.

Open the software and you're immediately presented with dozens of metrics, graphs, and numbers.

The easiest place to start isn't the metrics. It's understanding the movement itself.

The countermovement jump follows a predictable sequence of events. Every athlete progresses through the same six phases, from standing still to landing back on the ground.

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Once you understand these phases, every force plate metric has context and becomes much easier to interpret.

The Six Phases of the CMJ

1. Weighing

The athlete stands still while the force plate measures body weight and establishes the baseline for every calculation that follows. A noisy weigh in makes for unreliable data so make sure the athlete is standing still.

2. Unweighting

This phase initiates the jump as the athlete begins descending into the countermovement. Force briefly drops below body weight as they accelerate downward and build momentum.

3. Braking

The downward movement is slowed and eventually stopped. This phase reflects an athlete's ability to attenuate and create force to stop downward momentum. This phase sets them up for an explosive change of direction.

4. Propulsion

The athlete reverses direction and drives into the ground to generate upward velocity before takeoff. This is the classic "jump" phase.

5. Flight

The athlete leaves the ground. Jump height is simply the result of everything that happened during the previous phases. There is no force on the plate while the athlete is in the air.

6. Landing

The athlete returns to the force plate and "absorbs" impact forces, providing insight into landing strategy and force attenuation.

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The biggest takeaway is that jump height is only the outcome. The force-time curve explains how the athlete achieved that outcome.

Ready to Go Beyond Jump Height?

If you're ready to confidently interpret force-time curves and apply force plate testing in the real world, Join the Force Plate Accelerator.

Over three days, July 20th - 23rd, you'll learn how to analyze the CMJ from start to finish, understand the metrics that actually matter, and use force plate data to improve athlete performance, monitor readiness, and guide return-to-play decisions.

Whether you're new to force plates or looking to sharpen your analysis, the Force Plate Accelerator is designed to help you bridge the gap between data and coaching.

Learn Force Plates ⮕

I hope this helps,

Ramsey "Your Force Plate Guide" Nijem