Posture refers to the alignment of the body parts when standing in a relaxed stance. Good posture involves training the body to stand, sit and lie in positions that place the least strain on supporting muscles and ligaments. There is no single definition of "normal" posture as everyone's body is different. Maintaining proper posture can help decrease joint stress and strain, prevent back pain, and contribute to a good appearance. Poor posture is corrected through exercises and therapies that realign the body and strengthen weak muscles. Daily posture exercises can help reinforce good habits and balance.