The latissimus dorsi muscle is one of the largest muscles in the back. There are two configured symmetrically along the backbone. The muscle is median dorsally located, and it is partially covered by the trapezius. Plus, the muscle originates along the T7 region of the spine. Also, the muscle extends to its insertion point on the humerus, specifically at the becipital groove. The muscle also covers the lower tip of the scapula. When flexed, the muscle works at extending, adducting and rotating the arm. Also, the muscle assists with force expiration as well as deep inspiration. Because of the size and regular use, injury to this muscle can be partially debilitating. Injuries may include rips and tears. Also, once aggravated the latissimus dorsi muscle is often the source of chronic shoulder and neck pain, and it can cause tendinitis of the shoulder joint. The thoracordorsal nerve serves the muscle. This nerve branches from the brachial plexus's posterior cord and follows the route of the subscapular artery.