I promised to share some of the things that my physical therapist prescribed. The first (and easiest) range of motion exercise:
Pendulum: bend at the waist and let your arm dangle straight down, then swing it in around in circles. The trick is to not move your arm, but to just let it hang there and swing freely. I was told that doing this simplest of exercises correctly involves a slight sway of the body to make the arm swing around.
This exercise works even better with a small weight. A two-pound weight like the one pictured here can just be strapped around your wrist:
Having tried two different types of wrist/ankle weights, I can attest to the fact that the kind with the velcro strap going all the way around is better than the less expensive model with just a tiny tab. If you don’t have access to one of these, holding a water bottle or can of food in your hand can also provide the extra weight needed to turn your arm into a pendulum.
Do this 3-4 times a day for maximum benefit.
Disclaimer: this is not medical advice. Consult your personal physician for diagnosis and treatment of your medical issues.
Addendum: illustration of this exercise here
I’m finding that my shoulder feels much better as long as I stay away from my computer. Reaching for the mouse starts my shoulder hurting again. Fifteen minutes of reaching out for the mouse leads to my shoulder and arm aching for hours. Expect posting to be sparse until things improve.