Hey you, sitting at your computer: Sit up straight and don't slouch. The importance of having good posture at your desk, at your dinner table, and in school has been drilled into your head by the posture police. What about your posture while sleeping? Your body position and alignment during the sleeping hours is just as important as during the waking hours. Heck, you can spend up to half of your day sleeping, so of course sleep posture is important. Poor sleep posture can cause back pain, neck...