This document discusses posture, defining it as the position or pose of an individual's body when sitting, standing, walking, or lying down. It categorizes posture into active and inactive, and provides subcategories of sitting, standing, lying, and walking posture. The document also examines causes of poor posture such as hereditary factors, injuries, diseases, lack of exercise, and overloading. It describes three common postural deformities: scoliosis, kyphosis, and lordosis.