Begin with your feet hip width apart, if not slightly wider, and your hands at your side.

Raise your hands to your chest as you push your hips back and sit into a squat position. Be sure to put all of your weight in your heels when squatting. Make sure your knee is not surpassing the middle of your foot.

Explode out of the squat, lowering your hands back toward your side.

Modification:

Explode onto your toes.