The anconeus muscle (or anconaus/anconæus) is a small muscle on the posterior aspect of the elbow joint.
Some consider anconeus to be a continuation of the triceps brachii muscle.[1][2][3] Some sources consider it to be part of the posterior compartment of the arm,[4] while others consider it part of the posterior compartment of the forearm.[5]
The Anconeus muscle can easily be palpated just lateral to the olecranon process of the ulna.
[edit] Origin and insertion
Anconeus originates on the posterior surface of the lateral epicondyle of the humerus and is inserted on the ulna lateral to the olecranon from where it extends down on the dorsal side of the bone. [6]
[edit] Function
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Arteries and nerves of the back of the arm
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Its function is trivial in humans. It assists in extension of the elbow, where the triceps brachii is the principal agonist, and supports the elbow in full extension.[6] It also prevents the elbow joint capsule being pinched in the olecranon fossa during extension of the elbow. Anconeus also abducts the ulna and stabilizes the elbow joint.
[edit] Innervation
Anconeus is innervated by the radial nerve (cervical roots 7 and 8)[6] from the posterior cord of the brachial plexus. The somatomotor portion of radial nerve innervating anconeus bifurcates from the main branch in the radial groove of the humerus. This innervation pattern follows the rules of innervation of the musculature of the posterior forearm (extensor) compartment by the radial nerve.
[edit] Blood supply
Anconeus is supplied by the middle collateral artery from the profunda brachii artery.[6]
[edit] Additional images
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Posterior view of left humerus
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Posterior aspect of bones of left forearm
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Deep muscles of posterior surface of the forearm
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[edit] References
- ^ Williams, P. et al., 1995, Gray's Anatomy, 38th ed., Churchill Livingstone
- ^ Jones, W. et al.(eds) , 1953, Buchanan's Manual of Anatomy, 8th ed., Balliére, Tindall and Cox., pp. 496
- ^ Grant, J. & Basmajian J., 1965, Grant's Method of Anatomy, 7th ed., The Williams & Wilkins Company, Baltimore, pp. 163-164
- ^ "Dissector Answers — Axilla & Arm". http://anatomy.med.umich.edu/musculoskeletal_system/axilla_ans.html. Retrieved 2008-01-17.
- ^ "The Radius and Ulna". Archived from the original on 2008-06-11. http://web.archive.org/web/20080611032919/http://www.med.mun.ca/anatomyts/msk/forearm.htm. Retrieved 2008-01-17.
- ^ a b c d "Anconeus". The Hosford Muscle Tables. http://www.ptcentral.com/muscles/musclearms.html#anconeus. Retrieved February 2012.
