HOW: Begin in a kneeling position next to a wall. The knee that is up should be closest to the wall. Placing your elbow on the wall with your arm bent is the correct distance you should be from the wall. From here, extend your arm out on the wall and move it in a circular motion going up overhead and then behind you attempting a full circle. The closer you are to the wall the harder it will be.
FEEL: You should feel your shoulder muscles working as you complete the circle on the wall.
COMPENSATION: Keep your chest and shoulder still the entire time, only move the arm that is on the wall without rotating your chest.