@jakedduck1 and @artist01, This remains the most outstanding medical mystery of my life so far and neither my thoracic surgeon sil nor two orthopedic surgeons can explain it other than that the medically unsupervised home pt I did may have made the difference.

Before my youngest gs's birth, I was diagnosed with a torn rotator cuff and all three surgeons recommended surgery. Even I could see the tear on the scan. I put it off until after our newest arrival. Due to extensive pt after earlier fractures, I still had some of the "stretching" items and worked them. I am certainly not suggesting that this would work for any other person but it was an unbelievable experience to regain use of that arm without pain eventually. Some things are just weirder than weird, yes?

@jakedduck1, Hi Jake. I had my shoulder surgery in about 1992 and not aware of what type it was. My surgery was part of a Shoulder Surgery teaching situation, done by one of the top Orthos of the day, through the University of Calgary in Canada. I even have a tape of the surgery. (Macabre curiosity of an artist. Lol) The surgeon told me afterward that there was even a small bone missing, having been ground away by activity/pressure, etc. I was shifting large (5'x7' etc.) canvases around in my studio, painting on them, etc, which caused that much stress on my joint. ( I'm 5'2" and was 110 lbs). I was in terrific pain for over a year, prior to surgery. I'm sure you're very familiar with shoulder pain, having had 3 surgeries! Ouchie! I was supposed to have surgery on my other shoulder but passed.
PS, I just read @feisty's post. My surgery was Rotator Cuff!