The back supports the head and trunk, making it one of the body’s strongest yet most flexible areas. A vital part of the back is the spinal canal, which houses nerves that extend throughout the body. Because of the spine’s role, back injuries can sometimes cause pain in other areas.

The spine is made up of multiple vertebrae, the bony structures that form the backbone, separated by disks that cushion and support each segment. The cervical vertebrae are in the neck, the thoracic vertebrae are in the upper and mid-back, and the lumbar vertebrae are in the lower back. At the base of the spine is the sacroiliac (SI) joint.

Back muscles connect the spine to the shoulders, neck, and hips. Back pain is very common in adults, with muscle strain being one of the leading causes.