Radial Nerve

Authors

Affiliations

Nathaniel Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

Origin

Nerve roots: C5-T1¹

Motor branches

elbow extensors—the triceps brachii and anconeus—have a single source of nerve supply through the radial nerve²

Direct Muscular branches to:

• Brachialis (partial)
• Triceps brachii
• Anconeus
• Brachioradialis
• Extensors carpi radialis longus (ECRL)
• Extensors carpi radialis brevis (ECRB)

Radial n. Direct Muscle Innervations
Muscle	Origin	Insertion	Innervation	Action

Indirect Muscular branches via Posterior Interosseous Nerve¹

• Supinator
• Extensor digitorum
• Extensor digiti minimi
• Extensor carpi ulnaris
• Extensors pollicis brevis
• Extensors pollicis longus
• Extensor indicis
• Abductor pollicis longus

Radial n. Indirect Muscle Innervations
Muscle	Origin	Insertion	Innervation	Action

Cutaneous Branches

Radial Nerve Cutaneous Branches¹

• Articular brs. from radial n.: Capsule of the shoulder joint
• Articular brs. from posterior interosseous n.: Joint capsule of the wrist and four radial metacarpophalangeal joints
• Posterior brachial cutaneous n. 
• Inferior lateral brachial cutaneous n. 
• Posterior antebrachial cutaneous n.

Superficial Branches

• Dorsal digital nn.
• Ulnar communicating br.

References

1.

Gilroy AM, MacPherson BR, Wikenheiser JC, Voll MM, Wesker K, Schünke M, eds. Atlas of Anatomy. 4th ed. Thieme; 2020.

2.

Neumann DA, Kelly ER, Kiefer CL, Martens K, Grosz CM. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 3rd ed. Elsevier; 2017.