HOW: Start in the push up position with your hands directly underneath your shoulders and your legs straight back with your toes pushing into the ground. Push the ground away from you and lift your hips into the air. As your hips raise into the air, take one hand and reach for your opposite ankle(if you can’t reach your ankle, touch your lower leg, knee, or thigh). Stay strong with your other arm as you're pushing back with just that arm. Return to the starting position and repeat on the other side.
FEEL: You should feel a stretch in your back as you twist. You should also feel your shoulder muscles working.
COMPENSATION: Keep your legs straight as you lift your hips up, don’t bend your knees. Keep your elbow straight as you twist and reach with the other hand.