I had to go the other way, learn to sleep on the side because of a spinal fracture since anything else was too painful. Never went back. Shoulders are very fle

I had to go the other way, learn to sleep on the side because of a spinal fracture since anything else was too painful. Never went back. Shoulders are very flexible but also extremely weak and sensitive, they should rarely be used out of neutral position. I've taught martial arts for a long time and most issues I see with people's shoulders is due to (improper) overuse. My point is that maybe the cause of the problem isn't in bed at all. My experience says that sleeping on the side makes everything easier, from breathing to offloading the spine.