Learn about the latissimus dorsi muscle, one of the largest muscles of the back, that helps move and stabilize the shoulder and arm. Find out its location, innervation, blood supply, and common causes and treatments of injury. Learn about the anatomy of the latissimus dorsi muscle easily at Bodyworks Prime. Learn its origin, insertion, action, innervation, blood supply and more. Learn about the anatomy, function, and variations of the latissimus dorsi , a large, flat muscle on the back that stretches to the sides and behind the arm. The latissimus dorsi is involved in extension, adduction, internal rotation, and trunk movement of the shoulder joint. The latissimus dorsi muscle has a wide origin, primarily originating from the thoracic and lumbar vertebrae, lower ribs, and iliac crest (part of the pelvic bone). Insertion: The muscle fibers of the latissimus dorsi converge and insert into the floor of the intertubercular groove of the humerus, providing a solid attachment to the upper arm bone.
