HOW: Get a band set-up at shoulder height and you will face the anchor. Bring your shoulder up to 90 degrees, such that your upper arm is parallel to the floor. This is your starting point and you will maintain this position, then rotate your hand up towards the ceiling while trying to keep your elbow and shoulder still. Return your hand back down and repeat at a quick pace.
FEEL: You should feel the muscles on the outside and the back of your shoulder working as well as your shoulder blade muscles. Think about keeping your shoulder blade squeezed back as you perform this movement and keep that position as you rotate your hand up towards the ceiling.
COMPENSATION: Do not shrug your shoulder, do not move your head/neck, do not lean backwards, do not flare your elbow when your rotate your hand. Try to isolate this exercise to shoulder and arm movement only. Do not lose position of your shoulder, the goal is to rotate on an axis