I always use to sleep curled into a ball on my side. Would wake up with painful tight traps and low back/hip pain. We got a new hard memory foam bed two years ago and I’ve started doing yoga at night before bed and now I find it more comfortable to sleep on my back, hands on stomach.
Now I am sleeping on my back in a savasana position or maybe find a way to sleep on my side but without putting so much pressure on my shoulders.
I’ve kind of been wondering if there is some weird psychological aspect to my sleeping posture as well. I’ve become more open and trusting in general and more balanced and confident since I’ve been working more on meditating and mindful yoga. I always felt so vulnerable before and curling into a tight ball was comforting.
As an aside, I tore my left shoulder 5 years ago and back sleeping has helped that pain subside. It has a lot of scar tissue built up that I’m actively working on diminishing.
I don’t have any hard science to back it up but I know from personal experience if I go to bed lying on my stomach, I’m not gonna get a good night sleep and I am generally going to bed with some kind of stress because of a bad day or anticipating a stressful tomorrow. I’ve heard that from an evolution perspective our ancestors slept on their stomachs so they would be ready to get up and run if a predator happened to come upon them during their sleep.