To sleep on my back. Being a life-long side sleeper has caused a lot of shoulder and upper back problems that sometimes make it hard for me to reach out and type. I wish I'd done this ages ago. It's one of the hardest things I've had to learn.
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.
Then later I may move around and find another position.
I would suggest finding a good chiropractor and describing the problem.
Believe there's studies on amyloid plaque clearance differing b/n different positions. And I believe back sleeping has less of such than side.
Unfortunately for me I'm a coffin sleeper.
About 6 months ago, I switched to a split keyboard and it's made a big difference for me. Sitting with my arms shoulder width apart has taken a lot of the strain out of my neck and back.
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