Muscle Anatomy
latissimus dorsi
The latissimus dorsi covers a very wide area of the lower half and upper sides of the back.
Origin
The latissimus dorsi originates on the spinous processes of the lower thoracic and all the lumbar vertebrae, the back of the sacrum, the crest of the ilium, and the lower three ribs.
Insertion
It inserts on the upper anterior side of the humerus by a flat tendon attached parallel to the upper portion of the pectoralis major insertion.
Function
Pulls the shoulders downward and to the back.