The latissimus dorsi is a broad, flat muscle that spans the lower back and sides of the trunk. It originates from the spinous processes of T7 to T12, the thoracolumbar fascia, the iliac crest, and the lower three or four ribs. Some fibres may also attach to the inferior angle of the scapula. These fibres travel upward and laterally to insert into the floor of the intertubercular groove of the humerus. Functionally, it extends, adducts, and medially rotates the humerus. It’s heavily involved in p