Name Extensor pollicis longusPronunciation (eks-TEN-sor POL-uh-sus LONG-gus) Origin/Proximal Attachment Postero-lateral surface of ulnaInterosseous membraneAntebrachial fascia Insertion/Distal Attachment Distal phalanx of thumb Action/Relevance Extends distal phalanx of thumbExtends distal phalanx of thumbAssists to extend the hand at the wrist Innervation Radial nerve - posterior interosseous (C6, 7,8) | 
