They assist you every time you pick something up, whether it's a pen or a concrete block. They support posture while you sit in your chair, and they even work at night when you sleep. Your back is composed of three natural curves that form an S-shape. When your three natural curves are properly aligned, your ears, shoulders, and hips are in a straight line. Without support from strong, flexible muscles, your back loses its three natural curves.
Poor posture can lead to pain and serious injury.
When you use good posture, your back is aligned in three natural curves supported by strong, flexible muscles. Good posture helps prevent back strain and pain.