LATISSIMUS DORSI - ORIGIN: Through lumbar aponeurosis to spines T6-12 vertebrae & Spines of lumbar and sacral vertebrae and supraspinous ligaments & Posterior iliac crest & Directly from iliac crest & Lower 4 ribs INSERTION: Bottom of intertubercular groove of humerus ACTION: Extends, adducts, and rotates arm medially; draws shoulder downward and backward; helps in climbing