HOW: Position yourself lying face down. Bring your arms up in a Y shape to where your elbows are above your shoulder and elbows bent to 90 degrees. Rotate your hands and have your thumbs up and have your hands almost touching above your head creating a diamond shape. From here, squeeze your shoulder blade muscles lifting your elbows off of the ground and back down in a slow and controlled motion.
FEEL: You should feel the muscles in your shoulder blades working when you squeeze them together.
COMPENSATION: Keep your elbows above your shoulders at all times. Keep your elbows bent at 90 degrees. Make sure to engage your shoulder blade muscles to lift your elbows up.