Sleep experts say this position may be the most problematic. Why? Because it could result in back and neck pain. When you’re lying on your stomach, your head has to turn one way or the other. Doing this for hours at time can create stiffness, soreness or pain. If the only way you find comfort is by sleeping on your stomach, the key is to keep your body as flat as possible. You’ll want to use a thin pillow to avoid cocking your head back and straining your neck. Putting a travel pillow under your pelvis is another way to keep your spin in a neutral position. That said, stomach-sleeping may be good for those who snore, as this position helps the airways stay open.