Extensor Carpi Radialis Brevis (ECRB)

Authors

Affiliations

Nate Yomogida, PT, DPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, PT, DPT

Doctor of Physical Therapy

B.A. in Neuroscience

Figure 1: Left Humerus (Anterior view)¹

Figure 2: Muscles that move the Forearm²

Mucous sheaths of the dorsal hand¹

Transverse section of distal forearm¹

Transverse cut of the Hand¹

Reading list

• Wrist Extensor and Brachioradialis Muscles³
• ⁴
• MMT⁵

Muscle	Origin	Insertion	Innervation	Action
Extensor carpi radialis brevis	Lateral epicondyle of Humerus	3rd metacarpal base	Radial n. C7 - C8	Elbow: Weak flexion Wrist: Extension, Radial deviation

Origin

Lateral epicondyle of Humerus⁶

Insertion

Base of 3rd metacarpal⁶

Innervation

Posterior Interosseous N. (C7, C8)⁶

Action

• Elbow: Weak Flexion⁶
• Wrist: Extension, Radial deviation⁶

Notes

1.

Gray H. Anatomy of the Human Body. 20th ed. (Lewis WH, ed.). Lea & Febiger; 1918. https://www.bartleby.com/107/

2.

Betts JG, Blaker W. Openstax Anatomy and Physiology. 2nd ed. OpenStax; 2022. https://openstax.org/details/books/anatomy-and-physiology-2e/?Book%20details

3.

Donnelly JM, Simons DG, eds. Travell, Simons & Simons’ Myofascial Pain and Dysfunction: The Trigger Point Manual. Third edition. Wolters Kluwer Health; 2019.

4.

Neumann DA, Kelly ER, Kiefer CL, Martens K, Grosz CM. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 3rd ed. Elsevier; 2017.

5.

Weinstock D. NeuroKinetic Therapy: An Innovative Approach to Manual Muscle Testing. North Atlantic Books; 2010.

6.

Gilroy AM, MacPherson BR, Wikenheiser JC, Voll MM, Wesker K, Schünke M, eds. Atlas of Anatomy. 4th ed. Thieme; 2020.