Back is the part of the body that extends from the neck to the buttocks (rump). Its sides are formed by the ribs, which are attached to the vertebrae (bones that make up the spine). The scapulae are the shoulder blades below the neck and to either side of the spine. The pelvis (framework of bones of the lower trunk of the body) forms the base of the back. See Pelvis.
The back has many groups of muscles that perform different tasks. The postvertebral (behind the vertebrae) muscles hold the body erect and allow the back to be extended. The sacrospinalis muscles link the vertebrae and the pelvis. The trapezius, latissimus dorsi, levator scapulae, and rhomboidei muscles hold and manipulate (operate) the upper arm and scapulae.
Many people suffer from backaches (see Backache). Sometimes the intervertebral disk, the tissue that lies between the vertebrae, protrudes (sticks out) and presses on nerves. This condition is called a slipped disk, or herniated disk. It can cause severe pain in the lower back, thighs, and legs.
