On the side
For sleeping on your side, a high cushion is the best choice as it supports the neck so that the spine is in a straight line and the chest remains open.
On the back
If you prefer sleeping on your back, choose a slightly lower pillow to support the neck and keep the head in a naturally straight position to keep the spine in a straight line.
On the stomach
We do not recommend sleeping on your stomach, because the position of the neck becomes unnaturally twisted. If, however, you prefer sleeping on your stomach, a low pillow is best.