HOW: Standing with your arms at your side, bring one arm up in front of you as high as you can, palm facing in. Once you have your arm as high as you can, rotate your arm around to where your palm is facing out. As you rotate your arm out, rotate your arm and shoulder back until you can’t. At that point, rotate your hand back to the starting position and reverse the motion.
FEEL: You should feel the muscles in your shoulder working.
COMPENSATION: Keep your chest facing forward. Don’t twist back towards the moving arm. Slow and controlled motion, this is not about how fast you move your shoulder.