Dorsal Forearm Muscles

Question 1

What muscles make up the first, or superficial, layer of dorsal forearm muscles?

Answer 1

Extensor Carpi ulnaris
Extensor digiti minimi 
Extensor digitorum 
Extensor Carpi radialis brevis 
Extensor Carpi radialis Longus

Question 2

What muscles make up the second, or deeper, layer of dorsal forearm muscles?

Answer 2

Extensor indicis
Extensor pollicis Longus
Extensor pollicis brevis
Abductor pollicis Longus.

Question 3

What three proximal muscles acting on the dorsal forearm have unique origins, insertions, and actions?

Answer 3

Anconeus, supinator, brachioradialis

Question 4

Brachioradialis origin

Answer 4

Proximal 2/3rds of the lateral Supracondylar ridge of the humerus

Question 5

brachioradialis insertion

Answer 5

Lateral base of the styloid process of the radius

Question 6

Brachioradialis nerve

Answer 6

radial

Question 7

Brachioradialis action

Answer 7

Flexes at elbow, can initiate pronation and supination.

Question 8

Supinator (most proximal of deep group and deep to anconeus) origin

Answer 8

Superficial part- lateral Epicondyle

Deep part- Supinator crest on lateral ulna

Question 9

Supinator insertion

Answer 9

Proximal 1/3rd radius (wraps around radius) on anterior oblique line

Question 10

Supinator nerve

Answer 10

Deep radial (posterior interosseous)

Question 11

Supinator action

Answer 11

prime Supinator of forearm at elbow

Question 12

Extensor Carpi radialis longus origin

Answer 12

Lower 1/3 of lateral Supracondylar ridge or humerus

Question 13

Extensor Carpi radialis longus insertion

Answer 13

Dorsal surface of the base of second metacarpal

Question 14

Extensor Carpi radialis longus nerve

Answer 14

radial

Question 15

Extensor Carpi radialis longus action

Answer 15

Extends wrist and abducts (radially deviates) hand

Question 16

Extensor Carpi radialis brevis origin

Answer 16

Lateral Epicondyle of humerus and radial collateral ligament

Question 17

Extensor Carpi radialis brevis insertion

Answer 17

base of third metacarpal

Question 18

Extensor Carpi radialis brevis nerve

Answer 18

radial

Question 19

Extensor Carpi radialis brevis action

Answer 19

extends wrist and abducts (radially deviates) hands

Question 20

Extensor Carpi ulnaris origin

Answer 20

Common tendon from the lateral Epicondyle of humerus

Question 21

Extensor Carpi ulnaris Insertion

Answer 21

Dorsal surface of the base of the 5th metacarpal

Question 22

Extensor Carpi ulnaris nerve

Answer 22

interosseous branch of the radial nerve

Question 23

Extensor Carpi ulnaris action

Answer 23

Extends and adducts (ulnarly deviates) the hand at wrist.