HOW: Start this exercise upright. Squeeze the band on one end bringing your arm to your side, with the opposite arm elevate the arm in a Y formation (not purely up or across, but in between). Initiate the motion from the scapula and allow the arm to follow this motion.
FEEL: The muscles on the inside of your shoulder blade.
COMPENSATION: Avoid arching the back and shrugging the shoulder that is lifting up.