Your back is made up of the spine, ligaments, tendons, nerves, blood vessels and muscles. The spine is composed of bones called vertebrae. In between each vertebrae are small discs, which help to cushion the bones of the spine. A canal running down the center of your spine houses the spinal cord, which travels from the brain all the way down to the lower back. Your brain uses your spinal cord to 'talk' to other parts of your body.
Surrounding the spine are ligaments, tendons, nerves and muscles. The spine’s flexibility combined with the surrounding muscles makes the back very strong and flexible. The muscles of the back help you to move your head, neck and shoulders. Muscles lower in the back help you to bend forward and backward. Your back is also designed to help you maintain your center of gravity, allowing you to walk without falling or stumbling.