HOW: Anchor a band or cable high above your head. While standing, grab the band with the outside hand away from the anchor with your arm up and across your face and your elbow slightly bent. Your palm should face behind you, pull the band down and out as you rotate your palm facing to the front with your thumb pointing down.
FEEL: You should feel your shoulder blade muscles working.
COMPENSATION: Keep your upper trap muscles relaxed, don’t shrug your shoulders. Don’t twist your body, let your shoulder do all of the motion.