HOW: Start on all fours with your knees under your hips and your elbows under your shoulders and hands on the ground. Put your toes into the ground, then push into it lifting your body slightly off of the ground. Move your foot and hand forward at the same time followed by the other side. Keep doing this for the prescribed amount of reps. Pretend there is a cup of water on your back and you can't spill it in order to keep your back flat.
FEEL: You should feel your core, shoulder, and hip muscles working.
COMPENSATION: Keep your back flat, don’t arch it. Keep your body off of the ground. Maintain your chest towards the floor for the entirety of this movement.