AnatomyBasicsFirst look at bones and musclesExtensor pollicis brevis muscle

Extensor pollicis brevis muscle

Origins, insertions, innervation and function of the extensor pollicis brevis muscle.

Show transcript

Hey there everybody! It’s Matt from Kenhub, and in this tutorial, we will discuss the extensor pollicis brevis. The extensor pollicis brevis muscle is one of the five deep extensors of the forearm. This group of muscles can be easily palpated as they form the surface of the distal forearm and the wrist. The extensor pollicis longus lies on the medial side of the abductor pollicis longus and is found on the dorsal side of the forearm. The extensor pollicis brevis originates more distally at the posterior side of the radius and the interosseus membrane and has its insertion at the base of the proximal phalanx of the thumb.

Like all extensors of the forearm, this muscle is innervated by a deep branch of the radial branch which you’re seeing here highlighted in green on this image. The radial nerve divides into a superficial branch and deep branch at the height of the radial head. While the superficial branch runs along the brachioradialis, the deep branch continues between the two layers of the supinator. There, it penetrates the supinator muscle and branches off as the posterior interosseus nerve which is responsible for the innervation of almost all deep extensors.

A triangular depression lies at the radial side of the dorsum of the hand which becomes even more prominent during hand extension. It is commonly referred to as the anatomical snuffbox or radial fossa. The depression is framed by the radius and both the tendons of the extensor pollicis longus and of the extensor pollicis brevis.

The main function of the deep extensors is to move the joints of the hand and fingers. The extensor pollicis brevis extends and abducts the thumb in the saddle and at the metacarpophalangeal joints, which also leads to a radial deviation at the wrist.

This video is more fun than reading a textbook, right? If you want more videos, interactive quizzes, articles, and an atlas of human anatomy, click on the “Take me to Kenhub” button. It is time to say goodbye to your old textbooks and say hello to your new anatomy learning partner, Kenhub!

See you there!

Continue your learning

Video (You are here)

Extensor pollicis brevis muscle

Extensor pollicis brevis muscle

Origins, insertions, innervation and function of the extensor pollicis brevis muscle. [02:29]

Other videos

The deltoid muscle is a large and powerful muscle of the shoulder joint. On this video, we will explore the attachment points, innervation and functions of the deltoid. [06:59]

Triceps brachii muscle

Triceps brachii muscle

Origin, insertion and innervation of the triceps brachii muscle. [03:04]

Anconeus muscle

Anconeus muscle

Origin, insertion and innervation of the anconeus muscle. [02:29]

Biceps brachii muscle

Biceps brachii muscle

Origin, insertion, innervation and functions of the biceps brachii muscle. [03:32]

Coracobrachialis muscle

Coracobrachialis muscle

Origin, insertion, innervation and function of the coracobrachialis muscle. [02:22]

Subscapularis muscle

Subscapularis muscle

Origin, insertion, innervation and functions of the subscapularis muscle. [02:02]

Brachialis muscle

Brachialis muscle

Origin, insertion, innervation and functions of the brachialis muscle. [02:35]

Infraspinatus muscle

Infraspinatus muscle

Origin, insertion, innervation and functions of the infraspinatus muscle. [01:57]

Teres major muscle

Teres major muscle

Origin, insertion, innervation and functions of the teres major muscle. [02:23]

Teres minor muscle

Teres minor muscle

Origin, insertion, innervation and functions of the teres minor muscle. [02:45]

Functions of the arm muscles

Functions of the arm muscles

Anatomy and functions of the muscles of the upper arm. [02:06]

Functions of the shoulder muscles

Functions of the shoulder muscles

Anatomy and functions of the muscles of the shoulder. [02:27]

Lumbrical muscles of the hand

Lumbrical muscles of the hand

Origins, insertions, innervation and function of the lumbrical muscles of the hand. [02:10]

Palmar interossei muscles

Palmar interossei muscles

Origins, insertions, innervation and function of the palmar interossei muscles. [03:00]

Dorsal interossei muscles of the hand

Dorsal interossei muscles of the hand

Origins, insertions, innervation and function of the dorsal interossei muscles of the hand. [04:03]

Flexor digitorum profundus muscle

Flexor digitorum profundus muscle

Origins, insertions, innervation and function of the flexor digitorum profundus muscle. [02:27]

Flexor pollicis longus muscle

Flexor pollicis longus muscle

Origins, insertions, innervation and function of the flexor pollicis longus muscle. [02:09]

Pronator quadratus muscle

Pronator quadratus muscle

Origins, insertions, innervation and function of the pronator quadratus muscle. [02:01]

Supinator muscle

Supinator muscle

Origins, insertions, innervation and function of the supinator muscle. [02:47]

Abductor pollicis longus muscle

Abductor pollicis longus muscle

Origins, insertions, innervation and function of the abductor pollicis longus muscle. [02:22]

Extensor indicis muscle

Extensor indicis muscle

Origins, insertions, innervation and function of the extensor indicis muscle. [02:09]

Abductor pollicis brevis muscle

Abductor pollicis brevis muscle

Origins, insertions, innervation and function of the abductor pollicis brevis muscle. [02:10]

Adductor pollicis muscle

Adductor pollicis muscle

Origins, insertions, innervation and functions of the adductor pollicis muscle. [02:24]

Flexor pollicis brevis muscle

Flexor pollicis brevis muscle

Origins, insertions, innervation and functions of the flexor pollicis brevis muscle. [02:21]

Main muscles of the upper extremity

Main muscles of the upper extremity

Major muscles of the shoulder, upper arm, forearm and hand. [15:09]

Introduction to the muscular system

Introduction to the muscular system

Overview of the anatomy, function and main structures of the muscular system. [07:46]

Origin vs insertion

Origin vs insertion

Definition of the main differences between muscle origin and insertion. [04:46]

Quiz (Recommended next)

Main muscles of the upper extremity

Main muscles of the upper extremity

Major muscles of the shoulder, upper arm, forearm and hand.

Articles for further reading

Upper Limb muscles and movements

Upper Limb muscles and movements

This article describes the anatomy of the upper limb muscles, including their attachments, actions, and location. Learn this topic now at Kenhub!

Biceps brachii muscle

Biceps brachii muscle

Here you will find a description of the anatomy, supply, function and pathology of the Biceps brachii, a muscle of the arm. Start learning it now.

Triceps brachii muscle

Triceps brachii muscle

This article discusses the anatomy, supply, function and pathology of the Triceps brachii, a muscle of the arm. Start learning all about it here.

Triceps Brachii Muscle: Basic Anatomy

Triceps Brachii Muscle: Basic Anatomy

This article describes the anatomy of the triceps brachii muscle, including origins, insertions and innervation. Learn this topic now at Kenhub!

Brachialis muscle

Brachialis muscle

This is an article on the anatomy, supply, function and pathology of the Brachialis, a muscle of the arm. Learn everything about it here.

Coracobrachialis muscle

Coracobrachialis muscle

This is an article on the anatomy, supply, function and pathology of the Coracobrachialis, a muscle of the shoulder joint. Learn everything about it here.

The Deltoid Muscle is an important muscle of the shoulder. It acts as the main abductor of the shoulder joint. Learn all about it here.

Superficial flexors of the forearm

Superficial flexors of the forearm

This is an article about the anatomy, supply, function and pathology of the superficial flexors of the forearm. Learn all about these muscles here.

The deep flexors of the forearm

The deep flexors of the forearm

This is an article on the anatomy, supply, function and pathology of the deep flexor muscles of the forearm. Learn all about this group of muscles here.

The superficial extensors of the forearm

The superficial extensors of the forearm

This is an article about the anatomy, supply, function and pathology of the superficial extensors of the forearm. Learn all about these muscles here.

Deep extensors of the forearm

Deep extensors of the forearm

This is an article on the anatomy, supply, function and pathology of the deep extensor muscles of the forearm. Learn all about these muscles here.

The hypothenar muscles

The hypothenar muscles

This is an article about the anatomy, supply, function and pathology of the hypothenar muscles. Learn all about this group of muscles here.

This is an article on the anatomy, supply, function and pathology of a group of 4 hand muscles known as the thenar muscles. Read all about them here.

Lumbrical muscles of the hand

Lumbrical muscles of the hand

This is an article on the anatomy, function and pathology of the lumbrical muscles of the hand. Start learning this group of four muscles here.

Dorsal interossei muscles of the hand

Dorsal interossei muscles of the hand

This is an article on the anatomy, supply, function and pathology of the dorsal interossei muscles of the hand. Learn all about this group of muscles here.

Palmar interossei muscles

Palmar interossei muscles

This is an article on the anatomy and function of the palmar interossei. It also describes the existence of a fourth palmar interosseous. Learn them here.

Anatomy of Grip

Anatomy of Grip

This article will look at the anatomy of grip, including the different types of grip and the anatomical structures involved. Learn this topic now at Kenhub.

Eccentric muscle contraction

Eccentric muscle contraction

In this article we will describe the physiology of the eccentric muscle contraction. Learn this topic now at Kenhub.

Look up structures in the atlas

Main muscles of the upper extremity

Main muscles of the upper extremity

Major muscles of the shoulder, upper arm, forearm and hand.

Well done!