Extensor carpi radialis brevis muscle
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225059060
2008-07-11T18:09:40Z
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robot Modifying: [[ar:عضلة كعبرية قصيرة باسطة للرسغ]]
{{Muscle infobox |
Name = Extensor carpi radialis brevis |
Latin = musculus extensor carpi radialis brevis |
GraySubject = 125 |
GrayPage = 452 |
Image = ECR-brevis.png |
Caption = Posterior surface of the left forearm. Superficial muscles. The partially obscured extensor carpi radialis brevis is shown in blue. |
Origin = [[humerus]] at the anterior of [[Lateral epicondyle of the humerus|lateral epicondyle]] ([[common extensor tendon]]) |
Insertion = base of the [[3rd metacarpal]] |
Blood = [[radial artery]] |
Nerve = [[deep branch of the radial nerve]] |
Action = [[extensor]] and [[Abduction (kinesiology)|abductor]] of the [[hand]] at the [[wrist joint]] |
Antagonist = [[Flexor carpi radialis muscle]] |
MeshName = |
MeshNumber = |
DorlandsPre = m_22 |
DorlandsSuf = 12548854 |
}}
The '''Extensor carpi radialis brevis''' is shorter and thicker than the [[extensor carpi radialis longus|longus]], beneath which it is placed.
==Origin and insertion==
It arises from the [[lateral epicondyle of the humerus]], by a tendon common to it and the three following muscles; from the [[radial collateral ligament (elbow)| radial collateral ligament]] of the [[elbow-joint]]; from a strong [[aponeurosis]] which covers its surface; and from the intermuscular septa between it and the adjacent muscles.
The fibers end about the middle of the forearm in a flat tendon, which is closely connected with that of the preceding muscle, and accompanies it to the wrist; it passes beneath the [[Abductor pollicis longus]] and [[Extensor pollicis brevis]], then beneath the [[dorsal carpal ligament]], and is inserted into the dorsal surface of the base of the [[third metacarpal]] bone on its radial side.
==Relations==
Under the [[dorsal carpal ligament]] the tendon lies on the back of the radius in a shallow groove called Lister's tubercle, to the ulnar side of that which lodges the tendon of the [[Extensor carpi radialis]], longus, and separated from it by a faint ridge.
==Innervation==
Like all the muscles in the posterior [[forearm]], ECR brevis is supplied by a branch of the [[radial nerve]].
==Action==
It is an extensor, and an abductor of the hand at the [[wrist]] [[joint]]. That is, it serves to manipulate the wrist so that the hand moves away from the palm and towards the [[thumb]].
The muscle, like all extensors of the forearm, can be [[strength training|strengthened]] by exercise that resist its extension. A [[wrist roller]] can be used and [[wrist curl|reverse wrist curls]] with [[dumbbell]]s can performed.
==Additional images==
<gallery>
Image:Gray214.png|Bones of left forearm. Posterior aspect.
Image:Gray220.png|Bones of the left hand. Dorsal surface.
Image:Gray417_color.PNG|Cross-section through the middle of the forearm.
Image:Gray419.png|Posterior surface of the forearm. Deep muscles.
Image:Gray421.png|Transverse section across distal ends of radius and ulna.
Image:Gray422.png|Transverse section across the wrist and digits.
Image:Gray424.png|The mucous sheaths of the tendons on the back of the wrist.
</gallery>
==External links==
* {{MuscleLoyola|ecrb}}
* {{MuscleUWash|extcarpiradbrevis}}
* {{eMedicineDictionary|Extensor+carpi+radialis+brevis+muscle}}
{{Muscles of upper limb}}
[[Category:Muscles of the upper limb]]
[[ar:عضلة كعبرية قصيرة باسطة للرسغ]]
[[de:Musculus extensor carpi radialis brevis]]
[[es:Segundo radial externo]]
[[fr:Muscle court extenseur radial du carpe]]
[[hr:Kratki radijalni ispružač zapešća]]
[[id:Otot extensor carpi radialis brevis]]
[[hu:Rövid orsócsonti csuklófeszítő izom]]
[[ja:短橈側手根伸筋]]
[[pl:Mięsień prostownik promieniowy krótki nadgarstka]]
[[sv:Extensor carpi radialis brevis]]
[[th:กล้ามเนื้อเอกซ์เทนเซอร์ คาร์ไพ เรเดียลิส เบรวิส]]