A complex relationship of physical psychological and physiological conditions affects the mental and physical quality of sleep, which can be negatively affected by an insufficiently adapted sleeping system or an incorrect sleeping posture. The vertebral column is often poorly supported during sleep, leading to low back pain-one of the most persistent problems in the industrialized world. This unique book aims to create a scientific foundation for sleep research, bringing together engineering and medicine with elements of mechanics, physical therapy, mathematics, orthopedics, physics and ergonomics. It provides an overview of sleep aspects relevant to designers as well as comprehensive guidelines on proper support of the spine.