Corpus: Anconeus muscle
Definition
The anconeus muscle belongs to the group of upper arm muscles. It is morphologically and functionally closely related to the triceps brachii muscle.
Anatomy
The anconeus muscle originates from the lateral epicondyle of the humerus (upper arm bone), with additional fibers originating from the ulnar collateral ligament and the joint capsule of the elbow joint. It inserts at the lateral side of the olecranon and the proximal quarter of the posterior side of the ulnar shaft.
Innervation
The muscle is innervated by the radial nerve from the brachial plexus (C7-Th1).
Function
Functionally, the anconeus muscle acts as a modest extensor of the elbow joint, providing support to the triceps brachii muscle. Additionally, it plays a role in guiding the proximal ulna during pronation movements. Serving as a capsular tensioner, it helps to keep parts of the capsule out of the elbow joint.