One of my shoulders stopped working very well about three years ago. Hanging from a pull-up and chin-up bar helps me a lot.
I was waking up in the middle of the night unable to move my right arm. Then my arm started to ache all day and I was already suffering a greatly reduced range of motion. A physical therapist told me that my sleeping position, on my right side, matched with my 8-12 hours a day standing in front of a laptop and typing, was to blame.
I can't stop typing, and the frustration of trying to change my sleeping position is a monster. As if an aching dominant arm's shooting pains when moved were not hardship enough, running on to little sleep is a whole other category of horrendous. Issues start to compound. I was spending a lot of time wondering if this was now my life.
My physical therapist told me to hang from my chin-up bar, palms out. Just to hang there and to try and do it for 2 minutes a day. The first time I tried it, I didn't have the strength to even hang there for 5 seconds. I could do chin-ups with my palms facing in no problem, but just hanging on the bar palms out caused the impinged arm to start shaking and trembling. Over the course of a few days, I worked up to 30 seconds and maybe up to one minute hangs.
My arm felt better.
My arm improves for longer and longer periods of time after hanging. The sleeping position remains super important and I'm trying pillows and all sorts of rolling painfully around trying not to put pressure on the shoulder.
My favorite reading position includes me laying on the impinged shoulder.
Unintentionally, I stopped hanging from the bar for a few weeks. Unsurprisingly, the pain came right back with all its associated problems. I started hanging from the bar again and the pain is receding.