Stand next to the measurement device, facing it with feet shoulder-width apart
Reach upward with one arm and mark the highest point that can be touched on the wall or measurement device (this is standing reach height)
Prepare for the jump by bending at the knees and hips, lowering into a squat position
Explode upward with maximal effort, extending the hips, knees, and ankles to jump as high as possible
Swing the arms upward to help generate momentum and reach for the highest point possible on the measurement device
Land safely back on the ground with both feet