|Function:||Leg Ext (Vertical)|
Sit on squat box facing elevated platform. Position lower legs vertical or ankles slightly forward of knees. Place arms down to sides.
Swing arms forward. On arm's back swing, begin to lean torso forward. Swing arms forward again, shift body weight onto feet, and jump off ground onto elevated platform. Land feet on top of elevated platform.
Ideally, knees could be behind ankles (further back than what is shown) when initially seated. In this position, greater stretch reflex can be created through hips (via hamstrings) once torso rocks forward, just before jump. However, other hip extensors can engage in stretch-shortening cycle in lieu of hamstrings' optimized involvement. A plyo-platform, bench, stool, or chair can be used. Increase height of elevated platform as ability improves. Plyometric boxes or stacked mats may be used as elevated platform. Also see similar Box Squat Jump.