“The best possible sleeping posture is on the back (supine) in a firm bed with adequate support of the cervical lordosis. One solution for stomach sleepers is to have them use pillows under the chest to minimize head rotation. Side sleepers should concentrate on having sufficient pillow support between the head and neck not (squashed down by) the shoulder, a bed that supports the spine in a neutral position.
For some patients, foam pillows should be avoided because their springiness aggravates Trigger Point symptoms especially in the upper trapezius and sternocleidomastoid muscles.”
-Dr. Janet Travell and Dr. David Simons