In the very early stages after surgery, the basic pendulum movement may be the best exercise to try. Stand up straight and point both hands at the ground. Swing your operative arm back and forth. You may only be able to go 6 inches in either direction when you start. That's your baseline. Try to get at least 2 inches farther every day for the first five days. Swing your arm about 10 times, rest for 30 seconds and swing it 10 more times.
About a month after surgery, try isometric exercises. Place both hands in front of your chest with your palms touching. Press firmly with both palms and hold it for 3 seconds. Repeat 10 times, take a 30-second break and do another set.
Grab both ends of a 24-inch exercise band and hold it in front of you at waist level. Pull with both arms outward and hold for 3 seconds. Repeat 10 times and then do another set. Then, place the exercise band behind your back at hip level. Pull with both arms outward and hold for a count of three. Repeat 10 times and do another set.