ABSTRACT
A synergy of psychological, physiological, and physical conditions affects the mental and physical quality of sleep, as described throughout Chapters 1 and 2. The most important physical component is the sleep system (i.e., mattress+support structure+head cushion). It mainly affects our physical condition during the night and, consequently, also during the day. Due to an insufficiently adapted sleep system, the human body-especially the vertebral column-is often supported unsatisfactorily, resulting in low back pain or sleeping disorders. Since both body dimensions and body weight distribution have an important influence on the position of the vertebral column on a sleep system, every person ideally needs an individually adapted sleep system. In practice, however, this is not profitable, given manufacturing techniques at present. People are, therefore, subdivided into population classes, and a range of sleep systems is optimized in accordance with these classes.
