Elbow extension relies on which nerve roots and muscle?

• A. C6, C7, C8 - triceps
• B. C5, C6 - biceps
• C. C7, C8 - extensor digitorum
• D. C8, T1 - abductor digiti minimi

Answer: (A)

Elbow extension is performed by the triceps brachii. The triceps receives its motor input from the radial nerve, with the nerve roots contributing mainly from C6, C7, and C8. This is why matching the triceps with C6–C8 best fits the anatomy of elbow extension.

The other options don’t align with which muscle extends the elbow: the biceps flex the elbow (C5–C6, via the musculocutaneous nerve); extensor digitorum extends the fingers (radial nerve, typically C7–C8, but it’s finger extension, not elbow extension); and abductor digiti minimi is a hand muscle innervated by the ulnar nerve (C8–T1), not involved in elbow movement.