MSK - Muscles of the Posterior Forearm Flashcards
Name the superficial muscles of the posterior forearm (7)
- Brachioradialis
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Extensor digitorum
- Extensor digiti minimi
- Extensor carpi ulnaris
- Anconeus
What is the origin of brachioradialis?
Proximal aspect of the lateral supraepicondylar ridge of the humerus
Where does brachioradialis insert?
- Distal end of the radius
- Proximal to the radial styloid process
What is the innervation of brachioradialis?
Radial nerve (C5, C6)
What are the actions of brachioradialis?
- Flexion of the forearm at the elbow
assists biceps brachii
What is the blood supply of brachioradialis?
Radial recurrent artery
What is the origin of extensor carpi radialis longus?
Supracondylar ridge
Where does extensor carpi radialis longus insert?
Tendon attaches to metacarpal bone 2
What is the innervation of extensor carpi radialis longus?
Radial nerve (C6, C7)
What are the actions of extensor carpi radialis longus?
- Extension of the wrist
- Radial deviation of the hand at the wrist
What is the origin of extensor carpi radialis brevis?
Lateral epicondyle of the humerus
Where does extensor carpi radialis brevis insert?
Tendon attaches to metacarpal bone 3
What is the innervation of extensor carpi radialis brevis?
Radial nerve (C6, C7)
What are the actions of extensor carpi radialis brevis?
- Extension of the wrist
- Radial deviation of the hand at the wrist
What is the origin of extensor digitorum?
Lateral epicondyle of the humerus
Where does extensor digitorum insert?
- Tendon splits into four in the distal forearm
- Inserts into extensor hood of each finger
What is the innervation of extensor digitorum?
Deep branch of radial nerve (C6, C8)
What are the actions of extensor digitorum?
Extension of digits 2-4 at MCP and IP joints
What is the blood supply of extensor digitorum?
Posterior interosseous artery
What is the blood supply of extensor carpi radialis/brevis?
Radial artery
What is the origin of extensor digiti minimi?
Lateral epicondyle of the humerus
Where does extensor digiti minimi insert?
Base of 5th metacarpal
What is the innervation of extensor digiti minimi?
Radial nerve (C7, C8)
What are the actions of extensor digiti minimi?
- Extension of the wrist
- Ulnar deviation
What is the blood supply of extensor digiti minimi?
Posterior interosseous artery
What is the origin of anconeus?
Lateral epicondyle of the humerus
Blends with triceps brachii so is often undistinguishable
Where does anconeus insert?
Posterior and lateral part of the olecrannon
What is the innervation of anconeus?
Radial nerve (C7, C8)
What are the actions of anconeus?
- Moves ulna during pronation
- Extension of the forearm at the elbow joint
What is the blood supply of anconeus?
Middle collateral artery from the profunda brachii artery
How can the function of extensor digitorum be tested?
- Pronate the forearm
- Extend fingers against resistance
(Ask for consent)
