Muscles and Ligaments
Muscles and ligaments serve as supporting structures that allow the spine to remain upright and to move in a variety of positions. Spinal ligaments actually hold the vertebrae together and stabilize the spine. Ligaments are fibrous and tough tissues that form a criss-cross pattern in order to keep the spinal column together.
There are three major ligaments found in the spine. The anterior longitudinal ligament attaches to the front of each vertebra. The posterior longitudinal ligament runs from the brain to the tailbone vertically behind and beside the spinal canal. The third type of ligament is known as the ligamentum flavum; this ligament connects under the facet joints and forms a hood over the dura mater, thus protecting the spinal cord.
Spinal muscles are also attached to the spine and, like ligaments, serve to keep the spine stable. The body's complex muscular system allows for motion by manipulating thousands of intricate movements. Muscles are the only human tissues capable of contracting and relaxing. When a muscle contracts, the tissue becomes shorter and thicker. This series of muscle contraction and relaxation explains how the body moves. However, when a muscle is put under enough stress, it can spasm and tense up into knots; muscle strain is a common reason for back pain.