The first exercises just after surgery are generally passive, meaning you do not use the muscles in the injured shoulder to move the arm. Instead, they are designed to help increase the range of motion.
While lying on your back with your injured arm next to you, use your good arm to slowly move the injured arm, keeping the elbow straight through a 180-degree arc until it is next to your head. Then slowly lower the arm to its original position, making sure the shoulder remains completely relaxed.
While still lying on your back, put a pillow or towel under the elbow of the injured arm, then bend the elbow at a 90-degree angle and point your hand up. Use a dowel or stick and push the hand of the injured arm out away from the body until you feel it beginning to stretch.
To maintain range of motion in your injured arm, sit in a chair with it next to your body, then move your elbow through its full range without help from your good arm.
To maintain muscle strength and reduce swelling, squeeze a rubber ball or squeeze toy, even if your arm is still in a sling.
Your doctor or physical therapist will decide when to move on to more active exercises, but it usually happens about six to eight weeks after surgery and involves more active stretching of the shoulder.
One exercise is to stand and place the injured arm behind you with your thumb at the base of your spine. Slowly move it up the spine as far as you can and then back down again. You may need to use a towel at first to help with this one. With your good arm holding one end of the towel, drop it behind your head and grasp the other end with your other hand, then use your good arm to pull the injured one up.
Another exercise requires you to stand with your injured arm straight out in front of you, then move the arm slowly in front of you toward the other arm while keeping the elbow straight. Use your healthy arm to help stretch it further.
Strengthening the rotator cuff doesn't usually begin until at least 12 weeks after surgery and typically involves rubber tubing, which you can get from your physical therapist, and possibly some light weights.
Attach the tubing to a doorknob of a door that is locked or closed and won't easily open. With your injured arm at your side and the elbow bent at 90 degrees, stand perpendicular to the door with the good arm closest to it. Grab the end of the tubing with the injured arm and pull it outward away from your body until it is taut, then slowly allow it to be slack. After exercising in this direction, turn so the injured arm is closer to the door and pull the tubing in toward your body.
Another strength exercise is done while lying on your back, with the injured arm laying out away from you at shoulder height while holding a light weight with the palm up. Lift the weight while keeping the elbow straight until your arm is pointed straight up, then slowly lower the arm back into its original position.