The wedge shaped cushion with the hig side at the rear gives a position of the spine with activated muscles in the same manner as in the standing in the standing position, and the spine returns to its natural S-shape. This creates a lordosis of the lumbar spine during sitting. Characterized back pain can be avoided. Prolonged sitting in a comfortable and correct posture is facilitated. Therefore are the wedge-shaped cushions can be prefer in order to prevent low back pain and not for rehabilitation.