Muscles of the Back of Forearm : Superficial Flashcards
List the superficial muscles found in the back of the forearm, from lateral to medial(7)
- Brachio-radialis
- Extensor Carpi Radialis Longus
- Extensor Carpi Radialis Brevis
- Extensor Digitorum
- Extensor Digiti Minimi
- Extensor Carpi Ulnaris
- Anconeus
Origin of brachio-radialis
- From the upper 2/3 of lateral supracondylar ridge of humerus
- Lateral intermuscular septum of the arm
insertion of brachio-radialis
Into lateral surface of lower end of radius just above the styloid process
Nerve supply of brachio-radialis
Radial nerve (by a branch arising on the lateral side of the arm)
Actions of brachio-radialis
- Initiates pronation and supination of the forearm
- Flexion of the forearm in the midprone position (muscle of military salute)
Origin of Extensor Carpi Radialis Longus
- Lower 1/3 of lateral supracondylar ridge of humerus
- From lateral intermuscular septum of the arm
Insertion of Extensor Carpi Radialis Longus
Into the back of the base of the 2nd metacarpal bone
Nerve Supply of Extensor Carpi Radialis Longus
Radial nerve (by a branch arising on the lateral side of the arm)
Actions of Extensor Carpi Radialis Longus
- extension of the wrist
- Abduction (radial deviation) of the hand
Origin of Extensor Carpi Radialis Brevis
From the front of the lateral epicondyle of the humerus (common extensor origin)
Insertion of Extensor Carpi Radialis Brevis
Into the back of the base of the 3rd metacarpal bone
Nerve supply of Extensor Carpi Radialis Brevis
Posterior Interosseous Nerve (the deep branch of radial nerve)
Supplies muscle before it pierces supinator muscle
Actions of Extensor Carpi Radialis Brevis
- Extension of the wrist
- Abduction (radial deviation of the hand)
Origin of Extensor Digitorum
From the front of the lateral epicondyle of the humerus (common extensor origin)
Insertion of Extensor Digitorum
- Middle slip inserts into the base of the middle phalanx
- Two collateral slips are inserted into the base of the terminal phalanx
on the medial 4 fingers