Anconeus
Anconeus
Pronunciation: an-KOH-nee-us
Illustration: Anatomy Learning Platform (original) · CC0-1.0 (public domain dedication)
For beginners
A small helper muscle at the back of the elbow that assists the much larger triceps in straightening your arm, while also helping keep the joint steady.
Show the advanced explanation
Beyond assisting extension, the anconeus is thought to help stabilize the elbow joint capsule during forearm pronation/supination, acting as a dynamic joint stabilizer rather than a major force producer.
Structure & function
- Location
- A small, triangular muscle on the back of the elbow, just beside the triceps.
- Origin
- Lateral epicondyle of the humerus.
- Insertion
- Olecranon and upper posterior surface of the ulna.
- Main action(s)
- Assists the triceps brachii in extending the elbow; helps stabilize the elbow joint during forearm rotation.
- Joint(s) crossed
- Elbow joint
- Movement plane
- sagittal
- Innervation
- Radial nerve (C7–C8)
- In daily movement
- Works alongside the triceps any time the elbow straightens.
- In exercise
- A minor assistant to the triceps brachii in all elbow-extension exercises; not a prime mover on its own.
- Commonly confused with
- Easy to overlook as 'just part of the triceps' since it sits right beside it and shares a similar action.
- Common misconceptions
- It cannot be meaningfully isolated or specifically targeted by any common exercise — it is trained incidentally alongside the triceps.
Exercises that use this muscle
As a secondary / stabilizer
- Diamond Push-Up (secondary)
⚠ Safety note
Rarely a source of isolated injury; general elbow-safety principles apply.
Sources
“The anconeus assists elbow extension and stabilizes the elbow joint.”
Anatomy and Physiology 2e — OpenStax, Rice University · Ch. 11.5 Muscles of the Pectoral Girdle and Upper Limbs
Peer-reviewed textbook · License: CC BY-NC-SA 4.0 · Last checked 2026-07-19
Sign in to bookmark this and save notes.