[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anatomy](https://durgical.com/en/anatomy/) › [Upper limb](https://durgical.com/en/anatomy/region/upper-limb/) › Common extensor tendon [Muscular system](https://durgical.com/en/anatomy/system/muscular-system/) · [Upper limb](https://durgical.com/en/anatomy/region/upper-limb/) # Common extensor tendon The common extensor tendon anchors the muscles that lift the wrist and fingers to the outer elbow; tennis elbow starts here. [See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=upper_limb&select=common_extensor_tendon&side=r) Opens in the Durgical app, no sign-up needed. ## What it is The shared tendon of the wrist and finger extensors on the outer bump of the elbow. ## What it does Anchors the muscles that lift the wrist and fingers; tennis elbow starts here. ## Key points - Lateral epicondylitis is a degenerative tendinosis, not an inflammation, starting on the deep surface of the ECRB origin - Resisted wrist extension (Cozen), passive wrist flexion with the elbow straight (Mill) and resisted middle finger extension all load the origin - Radial tunnel syndrome and posterolateral instability mimic it; maximal tenderness a few centimetres distal, over the supinator, suggests the nerve ## Key facts **Attaches** Lateral epicondyle of the [humerus](https://durgical.com/en/anatomy/humerus/) to ECRB, extensor digitorum, [extensor digiti minimi](https://durgical.com/en/anatomy/extensor-digiti-minimi/) and ECU **Function** Shared origin of the forearm extensors; ECRB part degenerates in lateral epicondylitis (tennis elbow) **Tight in** Wrist flexion with the elbow straight ## Relations **Course** Arises from the front of the lateral epicondyle; the [extensor carpi radialis brevis](https://durgical.com/en/anatomy/extensor-carpi-radialis-brevis/) part lies deepest, directly on the lateral [elbow capsule](https://durgical.com/en/anatomy/elbow-joint-capsule/), partly overlapped by the [extensor carpi radialis longus](https://durgical.com/en/anatomy/extensor-carpi-radialis-longus/) and the [extensor digitorum](https://durgical.com/en/anatomy/extensor-digitorum/) **Deep** Radial collateral ligament, [annular ligament](https://durgical.com/en/anatomy/annular-ligament-of-the-radius/) and lateral capsule over the radiocapitellar joint; the lateral ulnar collateral ligament (LUCL) runs just behind **In front** [Brachioradialis](https://durgical.com/en/anatomy/brachioradialis/) and extensor carpi radialis longus from the supracondylar ridge; the [radial nerve](https://durgical.com/en/anatomy/radial-nerve/) divides into its superficial and deep branches in front of the elbow **Behind** [Anconeus](https://durgical.com/en/anatomy/anconeus/), between the lateral epicondyle and the olecranon **Below** [Supinator](https://durgical.com/en/anatomy/supinator/), which the [posterior interosseous nerve](https://durgical.com/en/anatomy/posterior-interosseous-nerve/) enters under the arcade of Frohse ## How to find it With the elbow bent to 90° and the forearm pronated, the lateral epicondyle is the bony point on the outer elbow; the tendon is felt just in front of and a little distal to its tip. Tenderness here, rather than over the radial head or further down the forearm, points to the tendon. ## Examination - Cozen test: elbow bent, forearm pronated, fist made and wrist extended against resistance; pain at the lateral epicondyle suggests lateral epicondylitis - Mill test: the elbow is straightened passively with the forearm pronated and the wrist flexed; lateral elbow pain from stretching the origin is positive - Resisted middle finger extension (Maudsley test): pain at the lateral epicondyle is positive; also painful in radial tunnel syndrome - Chair lift test: lifting a chair with the elbow straight and the palm down reproduces lateral elbow pain ## On imaging Ultrasound shows a thick, hypoechoic origin with tears, calcification or new vessels on Doppler. MRI shows high signal and tears at the ECRB origin and checks the lateral ulnar collateral ligament beneath. X-rays are usually normal, sometimes with calcification. ## Common problems - Tennis elbow (lateral epicondylitis): wear of the tendon, mostly the ECRB part, from repeated gripping and wrist lifting. - Pain on the outer elbow when gripping, lifting a cup or shaking hands; common in people aged 35-55, not only tennis players. ## How it is diagnosed Tenderness on the outer elbow bump and pain when lifting the wrist or middle finger against resistance. Ultrasound or MRI if unclear. ## Treatment - Activity changes, a forearm strap, and stretching and strengthening exercises; most cases settle within a year. - Injections are sometimes used; steroid injections give short-term relief only. - Surgery to clean out the damaged tendon when months of treatment fail. ## Clinical notes - Excessive surgical release or repeated corticosteroid injections can damage the LUCL and lead to posterolateral rotatory instability - Radial tunnel syndrome: pain is maximal a few centimetres distal, over the supinator, with pain on resisted supination - Lateral approaches to the elbow (Kocher, Kaplan) pass through or beside the extensor origin; pronating the forearm moves the posterior interosseous nerve away from the field ## Anatomical variants - The extensor group often shows extra bellies and doubled or missing tendon slips ## Development Its bony anchor, the lateral epicondyle, is the last of the six elbow ossification centres to appear (CRITOE order, around 11 years; ages vary between texts); before that the origin lies on cartilage that is invisible on X-rays. ## Test yourself Think of the answer, then tap the question to see it. ## Which muscles share the common extensor tendon on the lateral epicondyle? ECRB, extensor digitorum, extensor digiti minimi and ECU. ## What is the pathology of lateral epicondylitis in the common extensor tendon? A degenerative tendinosis, not an inflammation, starting on the deep surface of the ECRB origin. ## What is the Cozen test? Elbow bent, forearm pronated, fist made and wrist extended against resistance; pain at the lateral epicondyle suggests lateral epicondylitis. ## What condition mimics lateral epicondylitis, with maximal tenderness a few centimetres distal? Radial tunnel syndrome, with tenderness over the supinator and pain on resisted supination. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/anatomy/common-extensor-tendon/) Educational information, not medical advice. For any symptom, see a health professional. ## Its names **Official Latin (TA2)** tendo extensorius communis TA2 2498 **Official Spanish (DeCS)** Tendón común de los extensores **English (TA2)** Common extensor tendon **Also called** common extensor origin ## Related - [RCL (elbow)](https://durgical.com/en/anatomy/radial-collateral-ligament-of-the-elbow/) - [Humerus](https://durgical.com/en/anatomy/humerus/) - [ECRB](https://durgical.com/en/anatomy/extensor-carpi-radialis-brevis/) - [Extensor digitorum](https://durgical.com/en/anatomy/extensor-digitorum/) - [Extensor digiti minimi](https://durgical.com/en/anatomy/extensor-digiti-minimi/) - [ECU](https://durgical.com/en/anatomy/extensor-carpi-ulnaris/) Sources: Terminologia Anatomica (TA2); [Anatomy, Shoulder and Upper Limb, Wrist Extensor Muscles](https://www.ncbi.nlm.nih.gov/books/NBK534805/). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/anatomy/common-extensor-tendon/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/common-extensor-tendon/