|Function:||Leg Ext (Vertical)|
Stand in front of a secured box or platform.
Jump onto box using following steps: swing arms back, bend over at hips, flex knees, swing arms forward and upward, extend hips and knees. Land on box using following steps: pull arms out and downward to sides of body, Lift knees high, swing arms forward, and extend feet forward onto box or platform. Step down off of box or platform.
Rest between each jump is typically provided in effort to maximize jump height. However, jumps can be performed for reps with rests as long as it takes to step down off of box or platform and to get in starting position. Also see Box Jumps.
Spine is kept straight during jump push off and jumping up to short boxes. However spine flexes when legs are pulled up onto taller boxes. Consequently, spine also extends just before final landing.