1.Sleeping on your back is best as it provides the most support.
2. Wear a cervical collar  during sleep to reduce movement.
3. Use a cervical pillow or a small rectangular pillow to position under the nape of the neck while sleeping may also minimize pain.
4. Never use more than one pillow under the neck.  Doing so may put more stress on your neck.

For more information on back pain and treatments click here .