Summary Brachialis Origin Distal half of anterior surface of humerus Insertion Coronoid process and tuberosity of ulna Action Major flexor of forearm -- flexes forearm in all positions Innervation Medial half: Musculocutaneous nerve (C5,C6) Lateral half: Radial nerve (C5,C6,C7) Arterial Supply Muscular branches of brachial artery, recurrent radial artery