HOW: Start on your hands and your feet, have your hands positioned under your shoulders. To begin the exercise, assume a high plank position, while keeping your body straight lower your chest down towards the ground as far as you can, push up and towards the top rotate to one side by slightly lifting that hand off of the ground.
FEEL: This should feel like an upper body workout, your shoulders, chest, and triceps. You should also feel your core and your glutes/quads working to maintain a straight body from your heels to the back of your head.
COMPENSATION: Keep your body in a straight line, don't hike your hips high in the air or let your butt sag to the ground.