Upper limb
Musculocutaneous nerve
Nervus musculocutaneus
- Origin
- Terminal branch arising from the lateral cord of the brachial plexus (C5–C7)
- Insertion
- Pierces coracobrachialis, runs between biceps brachii and brachialis, and emerges at the lateral border of the biceps tendon as the lateral antebrachial cutaneous nerve
- Function
- Motor to the anterior arm flexor compartment (coracobrachialis, biceps brachii, brachialis); sensory to the lateral forearm skin down to the base of the thumb
- Innervation
- Mixed nerve driving primary elbow flexion and forearm supination
- Movement & chain
- Powers elbow flexion and forceful forearm supination (biceps brachii)
- Palpation
- Terminal cutaneous branch palpable in the antecubital fossa immediately lateral to the biceps brachii tendon
- Clinical
- Injury results in marked loss of elbow flexion strength and loss of sensation along lateral forearm; susceptible to traction in shoulder dislocations and during Latarjet coracoid transfer
- Segmental innervation
- C5, C6, C7 spinal roots
- In clinical practice
- Assessed via the biceps deep tendon reflex (C5–C6); monitored and protected during open and arthroscopic anterior shoulder reconstructions
- Region in the model
- Upper limb