Let's go over sleeping advice. First, it's either best to sleep on your side or your back. So not sleep on your stomach. The reason why is, if you're sleeping on your stomach you have to breathe. And, if this is your bed you're going to end up either turning like this or like this. And, this is not good for your neck. Second thing is, if you're going to sleep on your side you want to make sure that your pillow is thick enough. If again, if we take the example this is the bed and if I'm standing here to be in a neutral posture my pillow would have to be this thick before I even lie on it and it compresses. So, the problem is most people don't have a thick enough pillow when they're sleeping on the side. Generally, if you sleep on your side and your pillow is not thick enough your head will come down and then gravity will eventually pull you forward and you'll wind up on your stomach with your head turned to one side or the other. If your pillow is too high, then you'll generally roll to your back and you'll have some kind of twisted position. The easiest thing to do is lay on your side, stack up your pillows and lie comfortably and silently and try to feel your body. And if you feel like you're rolling forward, that means you've got to add a little bit more pillow height. And, if you feel like you're rolling backwards, then you've got to lower the pillow height.