The thoracolumbar fascia is a large portion of deep fascia in three parts found between the muscles of the back. As with any individual skeletal muscle, the muscles of the back are separated from adjacent muscles and held in place by layers of fibrous connective tissues called fascia. This connective tissue surrounds each muscle and may project beyond the end of its muscle fibers to form a cordlikemycontentbreak tendon. Fibers in a tendon intertwine to attach the fibers of the muscle to the bone. The fascia associated with the individual organs of the muscular system is part of a complete network of fascia that extends throughout the body. The part of this network that surrounds and penetrates the muscles is called deep fascia. It is continuous with the subcutaneous fascia that forms the fascia covering organs in various body cavities as well as the cavities themselves.