Extensor carpi radialis brevis muscle 239342 225059060 2008-07-11T18:09:40Z VolkovBot 3035831 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]]