During sleep I seem to have a need to wedge my limbs against a hard surface, often waking up with severe muscle and joint pain as a result. I don't just rest them there, but actively apply constant force. I wake up during the night with my wrist bent back uncomfortably under my face, and/or my thumb bent back, pushing hard into my elbow. Recently this has been escalating so that I woke up with 4 pillows under my head and my neck at an extreme angle, I took all but one pillow off the bed but then woke up to find myself pressing my head into the headboard, badly stressing my neck and back. The next night I made sure I lay down with at least a foot between my head and the headboard, only to wake having worked myself into the same position (pressing my head against the headboard). Next I tried sleeping upside-down as the bed has no base board, and woke up with my leg pushing hard into the headboard instead. Each time I try to eliminate the opportunity to do this I find a new way to do so in my sleep, even if it means using my own body to do so. This is leaving me with very sore and stiff muscles and joints and may be doing permanent damage for all I know. Has anyone else experienced this or know why I might be doing it?