Patients may say they woke up in pain because they slept in an odd position. I am not buying that explanation.
My hypothesis is that during sleep we tend to go into a twisted in utero position(s) that was comfortable during fetal development but now uncomfortable in life. The craniosacral fascial system remembers and holds that imprint(s).
One of our birth goals is to help work the strain out of the craniosacral fascial system to free the body of this old memory. We want to prevent a potential lifetime of suffering.