Latissimus Dorsi Muscle
Latissimus Dorsi, known as Lats for short is the broadest muscle of the back and one of the widest muscles. It is not used strenuously in common daily activities
Along the lumbodorsal fascia of the lower back, arising from the inferior thoracic and lumbar vertebrae, sacrum, iliac crest, and the four most inferior ribs.
Floor of the bicipital groove of the humerus.
The latissimus dorsi has several different functions, all of which involve movements of the arm. The primary function of the lat is the adduction of the arm. Another function of the lat is extension of the arm (from a flexed position) , as in swinging the arm toward the back. The lats internally/ medially rotates the arm, moving the front of the arm towards the body’s midline. When performed with a bent elbow, medial rotation of the arm brings the hand towards the chest, like when folding the arms or touching the elbow on the opposite arm.
Actions such as pull-up or chin-up or when pulling a heavy object down from a shelf above one’s head.