Starting Position: Stand facing a raised platform or a plyometric jump box, place your right foot on the top of the step or box, keep your left foot on the ground, hinge from the hips to lean forward, keep your arms by your side with your right arm in shoulder extension behind you and your left arm in shoulder flexion in front of you, keep your head level with your eyes looking at a point on the ground two-to-three feet in front of you.
Upward phase: Jump straight up into the air by explosively pushing your right foot in to the top of the box to create triple extension (ankle plantarflexion, knee and hip extension) while simultaneously pushing off with your left foot and swinging your right arm up and in front of your body to help generate upward momentum. As you jump into the air lift up your left leg in order to keep your feet level with each other and parallel with the floor.
Mid-air: as you are in the air quickly swing your left leg forward and your right leg back so that you will land with your left foot on top of the platform and your right leg behind you on the floor.
Landing: The most important components of the landing phase are correct foot position and avoiding excessive forward movement in your lower extremity which places additional stresses upon your knees. Attempt to land softly and quietly on the mid-foot, rolling backwards quickly towards the heels. Always push your hips backwards and drop them downwards to absorb the impacting forces associated with jumping. Avoid locking out your knees or quads on your landing as this may lead to potential knee injuries. Land with your trunk inclined slightly forward, head aligned with your spine and back rigid or flat. Keep your abdominal / core muscles engaged, stiffening your torso to protect your spine.
Exercise Variation: When you are learning this exercise focus on the soft landing and reset your body in the correct position for the next jump and pause for a moment between jumps to ensure good form. As you improve minimize the rest time so that you are rapidly moving from one jump to the next.
When jumping keep your spine straight and tall by contacting your abdominals (bracing) and be sure to perform the same number of repetitions on each leg.