The anconeus muscle (or anconaeus/anconæus) is a small

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

on the posterior aspect of the

elbow The elbow is the region between the upper arm and the forearm that surrounds the elbow joint. The elbow includes prominent landmarks such as the olecranon, the cubital fossa (also called the chelidon, or the elbow pit), and the lateral and t ...

joint. Some consider anconeus to be a continuation of the

triceps brachii muscle The triceps, or triceps brachii (Latin for "three-headed muscle of the arm"), is a large muscle on the back of the upper limb of many vertebrates. It consists of three parts: the medial, lateral, and long head. All three heads cross the elbow jo ...

. Some sources consider it to be part of the

posterior compartment of the arm Posterior may refer to: * Posterior (anatomy), the end of an organism opposite to anterior ** Buttocks, as a euphemism * Posterior horn (disambiguation) * Posterior probability The posterior probability is a type of conditional probability that ...

, while others consider it part of the

posterior compartment of the forearm The posterior compartment of the forearm (or extensor compartment) contains twelve muscles which primarily extend the wrist and digits. It is separated from the anterior compartment by the interosseous membrane between the radius and ulna. Struc ...

. The anconeus muscle can easily be palpated just lateral to the

olecranon The olecranon (, ), is a large, thick, curved bony process on the proximal, posterior end of the ulna. It forms the protruding part of the elbow and is opposite to the cubital fossa or elbow pit (trochlear notch). The olecranon serves as a lever ...

process of the

ulna The ulna or ulnar bone (: ulnae or ulnas) is a long bone in the forearm stretching from the elbow to the wrist. It is on the same side of the forearm as the little finger, running parallel to the Radius (bone), radius, the forearm's other long ...

Structure

Anconeus originates on the posterior surface of the

lateral epicondyle of the humerus The lateral epicondyle of the humerus is a large, tuberculated eminence, curved a little forward, and giving attachment to the radial collateral ligament of the elbow joint, and to a tendon common to the origin of the supinator and some of the e ...

and inserts distally on the superior posterior surface of the ulna and the lateral aspect of the olecranon.

Innervation

Anconeus is innervated by a branch of the

radial nerve The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the Posterior compartment of the ...

(cervical roots 7 and 8) from the posterior cord of the

brachial plexus The brachial plexus is a network of nerves (nerve plexus) formed by the anterior rami of the lower four Spinal nerve#Cervical nerves, cervical nerves and first Spinal nerve#Thoracic nerves, thoracic nerve (cervical spinal nerve 5, C5, Cervical spi ...

called the nerve to the anconeus. The somatomotor portion of radial nerve innervating anconeus bifurcates from the main branch in the radial groove of the

humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extrem ...

. This innervation pattern follows the rules of innervation of the musculature of the posterior forearm (extensor) compartment by the radial nerve.

Function

Its role in elbow extension 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. It also prevents the elbow joint capsule being pinched in the

olecranon fossa The olecranon fossa is a deep triangular depression on the posterior side of the humerus, superior to the trochlea. It provides space for the olecranon of the ulna during extension of the forearm. Structure The olecranon fossa is located ...

during extension of the elbow. Anconeus also abducts the ulna and stabilizes the elbow joint. Anconeus serves to make minute movements with the

radius In classical geometry, a radius (: radii or radiuses) of a circle or sphere is any of the line segments from its Centre (geometry), center to its perimeter, and in more modern usage, it is also their length. The radius of a regular polygon is th ...

on the

. In making slight abduction of the ulna, it allows any finger to be used as an axis of rotation of the forearm.

Blood supply

Anconeus is supplied by the

middle collateral artery The medial collateral artery (also known as the middle collateral artery) is a branch of profunda brachii artery that descends in the middle head of the triceps brachii and assists in forming the anastomosis with the interosseous recurrent artery ...

from the

profunda brachii artery The deep artery of arm (also known as deep brachial artery) is a large artery of the arm which arises from the brachial artery. It descends in the arm before ending by anastomosing with the radial recurrent artery. Structure Origin The deep ...

Clinical significance

Trauma to the nerve supply of the anconeus muscle can usually result from a shoulder dislocation or fractures of the upper part of the

or around the

, or any injury that damages the radial nerve. Harm inflicted upon the radial nerve through these mechanisms can paralyze the anconeus muscle as well as other extensors of the

and

wrist In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; "The wrist contains eight bones, roughly aligned in two rows, known as the carpal ...

. There are no specific acquired injuries that exclusively affect the anconeus muscle; however, any disease that compromises muscular functions, particularly arm extension (i.e. muscular dystrophy) will affect this particular accessory muscle.

Heterotopic ossification Heterotopic ossification (HO) is the process by which bone tissue forms Heterotopia (medicine), outside of the skeleton in muscles and soft tissue. Symptoms In traumatic heterotopic ossification (traumatic myositis ossificans), the patient may ...

can result from certain trauma as it is an abnormal growth of osseous tissue in non-osseous tissue (e.g. muscle tissue). The condition is usually found in the hips, although there have been documented cases of certain individuals with it occurring in the arms and legs. The cause for the process to initiate is not well understood, only that it typically results from surgery or trauma.

History

Etymology and spelling

''Anconeus muscle'' is the anglicized form of the Latin expression ''musculus anconaeus'', as can be found in the ''

Nomina Anatomica ''Nomina Anatomica'' (''NA'') was the international standard on human anatomic terminology from 1895 until it was replaced by '' Terminologia Anatomica'' in 1998. In the late nineteenth century some 30,000 terms for various body parts were in us ...

'' as ratified in

Basel Basel ( ; ), also known as Basle ( ), ; ; ; . is a city in northwestern Switzerland on the river Rhine (at the transition from the High Rhine, High to the Upper Rhine). Basel is Switzerland's List of cities in Switzerland, third-most-populo ...

in 1895His, W. (1895). ''Die anatomische Nomenclatur. Nomina Anatomica. Der von der Anatomischen Gesellschaft auf ihrer IX. Versammlung in Basel angenommenen Namen''. Leipzig: Verlag Veit & Comp. and in

Jena Jena (; ) is a List of cities and towns in Germany, city in Germany and the second largest city in Thuringia. Together with the nearby cities of Erfurt and Weimar, it forms the central metropolitan area of Thuringia with approximately 500,000 in ...

in 1935.Kopsch, F. (1941). ''Die Nomina anatomica des Jahres 1895 (B.N.A.) nach der Buchstabenreihe geordnet und gegenübergestellt den Nomina anatomica des Jahres 1935 (I.N.A.)'' (3. Auflage). Leipzig: Georg Thieme Verlag.Stieve, H. (1949). ''Nomina Anatomica. Zusammengestellt von der im Jahre 1923 gewählten Nomenklatur-Kommission, unter Berücksichtigung der Vorschläge der Mitglieder der Anatomischen Gesellschaft, der Anatomical Society of Great Britain and Ireland, sowie der American Association of Anatomists, überprüft und durch Beschluß der Anatomischen Gesellschaft auf der Tagung in Jena 1935 endgültig angenommen.'' (4th edition). Jena: Verlag Gustav Fischer. The anatomic Latin adjective ''anconaeus'' was written as ''anconeus'' in the subsequent edition of the ''Nomina Anatomica'' as authorized in 1955 in

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

,International Anatomical Nomenclature Committee (1955). ''Nomina Anatomica'' . London/Colchester:Spottiswoode, Ballantyne and Co. Ltd. without any further explanation of this specific diphthong reduction. The following edition of 1961 specified its policy by stating that: ''All diphthongs should be eliminated''.International Anatomical Nomenclature Committee (1966). ''Nomina Anatomica''. Amsterdam: Excerpta Medica Foundation. Although a selected number of monophthongizations was reverted, subsequent editions of the ''Nomina Anatomica'' and its most recent outing ''

Terminologia Anatomica ''Terminologia Anatomica'' (commonly abbreviated TA) is the international standard for human anatomy, human anatomical terminology. It is developed by the Federative International Programme on Anatomical Terminology (FIPAT) a program of the Inter ...

'' insisted on writing ''musculus anconeus''.International Anatomical Nomenclature Committee (1977). ''Nomina Anatomica, together with Nomina Histologica and Nomina Embryologica''. Amsterdam-Oxford: Excerpta Medica.International Anatomical Nomenclature Committee (1983). ''Nomina Anatomica, together with Nomina Histologica and Nomina Embryologica''. Baltimore/London: Williams & WilkinsInternational Anatomical Nomenclature Committee (1989). ''Nomina Anatomica, together with Nomina Histologica and Nomina Embryologica''. Edinburgh: Churchill Livingstone.Federative Committee on Anatomical Terminology (FCAT) (1998). ''Terminologia Anatomica''. Stuttgart: Thieme Despite the earlier preference of the ''Nomina Anatomica'' for ''anconaeus'' no

ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

form ἀγκωναῖος is attested.Hyrtl, J. (1880). ''Onomatologia Anatomica. Geschichte und Kritik der anatomischen Sprache der Gegenwart.'' Wien: Wilhelm Braumüller. K.K. Hof- und Universitätsbuchhändler. In

modern Greek Modern Greek (, or , ), generally referred to by speakers simply as Greek (, ), refers collectively to the dialects of the Greek language spoken in the modern era, including the official standardized form of the language sometimes referred to ...

the expression ἀγκωνιαίος μυςSchleifer, S.K. (Ed.) (2011). ''Corpus humanum, The human body, Le corps humain, Der menschliche Körper, Il corpo umano, El cuerpo humano, Ciało człowieka, Människokroppen, Menneskekroppen, Τό ανθρώπινο σῶμα, ЧЕЛОВЕК.'' FKG. is used, with the from ''anconaeus'' deviating adjective ἀγκωνιαίος.Triepel, H. (1910). ''Die anatomischen Namen. Ihre Ableitung und Aussprache. Mit einem Anhang: Biographische Notizen.''(Dritte Auflage). Wiesbaden: Verlag J.F. Bergmann. Anconaeus is derived from the ancient Greek noun, ἀγκών.Kraus, L.A. (1844). ''Kritisch-etymologisches medicinisches Lexikon'' (Dritte Auflage). Göttingen: Verlag der Deuerlich- und Dieterichschen Buchhandlung. 'Ακών can be translated as ''bend of the arm'' Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with the assistance of. Roderick McKenzie.'' Oxford: Clarendon Press. or ''elbow''. The expression ''musculus anconaeus'' was translated into English as ''elbow muscle'' in 1907 in the English translationBarker, L.W. (1907). ''Anatomical terminology with special reference to the NA With vocabularies in Latin and English and illustrations.'' Philadelphia: P. Blakiston's Son & Co. of the first edition of the ''Nomina Anatomica''.

Additional images

References

{{DEFAULTSORT:Anconeus Muscle Elbow extensors Muscles of the upper limb