Innervation Motor Sensory lateral antebrachial cutaneous nerve forearm sensory Origin C5,6,7 superior trunk lateral cord musculocutaneous nerve branch to coracobrachialis branch to biceps branch to brachialis lateral antebrachial cutaneous nerve (terminal branch) Course Pierces Coracobrachialis pierces coracobrachialis 3-8 cm distal to coracoid gives branch to coracobrachialis Splits biceps and brachialis runs between biceps and brachialis in the anterior compartment to enter the lateral aspect of the arm gives branch to biceps and brachialis Pierces deep fascia lateral to biceps brachii a little above the elbow it pierces the deep fascia lateral to the tendon of the biceps brachii Becomes lateral antebrachial cutaneous nerve (terminal branch) emerges lateral to distal bicep tendon and brachoradialis to form lateral antebrachial cutaneous nerve Injury & Clinical Conditions Musculocutaneous Nerve Inury usually iatrogenic during deltopectoral approach with dissection or retraction medial to conjoint tendon