During a wakeful moment of the night I got to wondering... My preference is to sleep on my side (right or left will do), but I will hold my arms in different positions depending upon which side. When I sleep on my left side I tend to fold my arms across my chest. When I sleep on my right I am more likely to extend one arm and tuck the other under the pillow. Somehow or other, without making a conscious decision, I have determined that these positions are the most comfortable and conducive to letting the rest of my body relax and rest.
I never thought much about sleeping positions until Michael J. Fox was posed in one in the movie Back to the Future. His "top" arm was extended behind him, while the rest of his body faced forward.
What about you? What do you do with your arms while you sleep?