Forearm Extensor Muscles - Origins, Insertions, and Actions, with Video Presentation

Posted on 25 Oct 2015 22:49



See also Forearm Flexor Muscles - Origins, Insertions, and Actions, with Video Presentation.

The following is information on the extensor muscles of the forearms. These videos were produced to help students of human anatomy at Modesto Junior College study their anatomical models.

They are done with models showing the muscular structure of the arm.

The following two videos present an overview of the major flexor muscles of the forearm, which are the muscles of the posterior compartment.

Each video is followed by information on the origin, insertion, and actions of each muscle covered in the video.

Forearm - Extensors Muscles Part 1

Brachioradialis

Origin: distal two-thirds of lateral condyloid ridge of humerus

Insertion: distal end of radius at styloid process

Action: flexion of elbow, pronation: supinated to neutral, supination: pronated to neutral

Extensor Carpi Radialis Brevis

Origin: lateral epicondyle of humerus

Insertion: base of third metacarpal

Action extension of wrist, abduction of wrist, weak extension of elbow

Extensor Carpi Radialus Longus

Origin: lower third of lateral supracondylar ridge of humerus and epicondyle of humerus

Insertion: base of second metacarpal

Action: extension of wrist, abduction of wrist, weak extension of elbow

Extensor Digitorum

Origin: lateral epicondyle of humerus

Insertion: four tendons to bases of middle and distal phalanges of the four fingers

Action: extension of the second, third, fourth and fifth phalanges at the metacapophalangeal joints, extension of wrist, weak extension of elbow

Forearm - Extensor Muscles Part 2

Exstensor Digiti Minimi

Origin: lateral epicondyle of humerus

Insertion: base of middle and distal phalanxes of fifth phalange of little finger

Action: extension of little finger at metacarpophalangeal joint, weak wrist extension

Anconeus

Origin: posterior surface of lateral condyle of humerus

Insertion: posterior surface of olecranon process of ulna

Action: extension of elbow

Abductor Pollicis Longus

Origin: posterior aspect of radius and midshaft of ulna

Insertion: base of first metacarpal

Action: abduction of thumb at carpometacarpal joint, abduction of wrist

Extensor Pollicis Brevis

Origin: posterior surface of lower middle radius

Insertion: base of proximal phalanx of thumb

Action: extension of thumb at metacarpophalangeal joint, weak wrist extension

This page created 25 Oct 2015 22:49
Last updated 18 Jul 2016 19:34

© 2016 by Eric Troy and Ground Up Strength. All Rights Reserved. Please contact for permissions.