Extensor carpi radialis Medial head of triceps brachii Pectoralis major (sternal head is cut) Lateral head of triceps brachii Acromion process Clavicle Humerus Deltoid Brachialis Extensor digitorum Spine of scapula Palmaris longus Brachioradialis Extensor carpi radialis Radial nerve Brachial plexus Radial artery Ulnar nerve Biceps Brachii