Anatomy of the muscles that move the spine

Among the muscles of the spine, some bend it backward, and some bend it forward. From this basic movement other movements arise.

The muscles that deflect backward are given a special name for the muscles of the spine. These are two muscles, each of which is considered to be composed of twenty-three muscles, going to each muscle from all the vertebrae, for from each vertebra, except the first, fibers go obliquely to this muscle. If these muscles are stretched moderately, they keep the spine straight, but if they are stretched excessively, they tilt it back. When the muscle located on the side begins to move, it tilts the spine in its direction.

As for the muscles that tilt forward, there are two pairs of them; one pair is located at the top and belongs to the muscles that move the head and neck and run along both sides of the esophagus. Their lower end adjoins the five upper thoracic vertebrae in some people, and four in most people, while the upper end goes to the head and neck.

Two muscles are located below these muscles and they are called the psoas. These muscles start from the tenth and eleventh thoracic vertebrae, go down and tilt the spine, releasing it. For the middle of the spine to move, the presence of these muscles is enough, because the spine, when bending forward, backward or to the side, follows the movement of the ends of the muscles.