Extensor Carpi Radialis Brevis

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Original EditorUchechukwu Chukwuemeka

Top Contributors-Uchechukwu ChukwuemekaandKim Jackson

Original Editor-

Top Contributors-Uchechukwu ChukwuemekaandKim Jackson

Description[edit|edit source]

ECR-brevis.png

Extensor carpi radialis brevis (ECRB) is a short muscle emerging underneath theextensor carpi radialis longusand both muscles share a common tendinous synovial sheath[1]. It is an extensor muscle located superficially at the posterior compartment of the forearm.

Origin[edit|edit source]

It originates from the common extensor tendon with extensor carpi ulnaris, extensor digiti minimi, and extensor digitorum at the Lateral epicondyle ofhumerustogether[2].

Insertion[edit|edit source]

It attaches at dorsal surface of the base of the 3rdmetacarpal[1]

Nerve[edit|edit source]

ECRB is innervated by the deep branch ofradial nerve(7th and 8th cervical nerve root) before the nerve courses through the two heads of thesupinator muscle[1][3]

Artery[edit|edit source]

The main blood supply to ECRB is from the radial artery. Other augmentation are from the radial collateral branch from profunda brachii and the radial recurrent artery[3].

Function[edit|edit source]

ECRB extends and abducts the wrist[2][3][1]

Clinical relevance[3][edit|edit source]

Lateral epicondylitispresents as pain on the lateral aspect of the elbow with or without loss of grip strength that is aggravated with activity and it will most likely have extensor carpi radialis brevis muscle affectation.

In cases of radial nerve compromise proximal to its division to deep and superficial branches at thecubital fossa, then some functional loss of wrist and digits extension will be present.

Assessment[edit|edit source]

With the hand in pronation, the ECRB muscle can be palpated during extension and abduction of the wrist against resistance.

[4]

References[edit|edit source]

  1. 1.01.11.21.3Moore, KL, Dalley, AF, Agur, AM. Clinically oriented anatomy. 7th ed. Baltimore, MD: Lippincott Williams & Wilkins, 2014
  2. 2.02.1Drake, RL, Vogl, W, Mitchell, AW, Gray, H. Gray's anatomy for Students 2nd ed. Philadelphia : Churchill Livingstone/Elsevier, 2010
  3. 3.03.13.23.3Walkowski AD, Goldman EM. Anatomy, Shoulder and Upper Limb, Forearm Extensor Carpi Radialis Brevis Muscle. Available from:https://www.ncbi.nlm.nih.gov/books/NBK539719/(accessed 26 July 2019)
  4. OTstudentVids. MMT of Flexor Carpi Radialis/Ulnaris and Extensor Carpi Uln. Available from:https://www.youtube.com/watch?v=31Wbe7xv8Jk[last accessed 29/3/2019]