HOW: Begin in a seated position underneath a pulley system. With one hand, hold onto the pulley with your palm facing you and your arm out in front of you at an angle. Make sure that arm is completely relaxed. Use the opposite arm to pull that arm up as much as you can tolerate. Let gravity and the weight of your arm pull it back down to the starting position. Repeat for as many reps as prescribed.
FEEL: You should feel a stretch in your shoulder. It may be uncomfortable - that is normal!
COMPENSATION: Keep the arm you are working relaxed, let the other arm do all of the work!