LATISSIMUS DORSI

ORIGIN
Spine T7, spinous processes and supraspinous ligaments of all lower thoracic, lumbar and sacral vertebrae, lumbar fascia, posterior third iliac crest, last four ribs (interdigitating with external oblique abdominis) and inferior angle of scapula
INSERTION
Floor of bicipital groove of humerus after spiraling around teres major
ACTION
Extends, adducts and medially rotates arm. Costal attachment helps with deep inspiration and forced expiration
NERVE
Thoracodorsal nerve (C6, 7, 8) (from posterior cord)