Anconeus
Musculus anconeus
A small triangular muscle on the back of the elbow, from the lateral epicondyle to the olecranon. It assists extension and stabilises the elbow.
Overview
Anconeus is partly continuous with the medial head of triceps. It runs from the posterior surface of the lateral epicondyle of the humerus to the lateral side of the olecranon and the upper posterior surface of the ulna. It assists triceps in extending the elbow, tenses the joint capsule so it is not pinched during extension, and stabilises the ulna during pronation and supination. It is supplied by a branch of the radial nerve that descends through the medial head of triceps.
Anatomy
- Origin
Posterior surface of the lateral epicondyle of the humerus.
- Insertion
Lateral surface of the olecranon and the upper posterior surface of the ulna.
- Action
Assists triceps in elbow extension; abducts the ulna during pronation; stabilises the elbow.
- Innervation
Radial nerve (branch to anconeus via the medial head of triceps).
- Nerve roots
C7–C8 (T1)
- Arterial supply
Middle collateral artery (from the profunda brachii) and recurrent interosseous artery.
Function
- Assists elbow extension
- Tenses the capsule and stabilises the elbow during forearm rotation
Compiled from standard anatomy and physiology references — see the Muscular System sources. For education only; not medical advice.