Musculoskeletal Anatomy: Forearm

Question 1

What are the muscles of the anterior compartment of the forearm?

Answer 1

[First layer: flexor carpi radialis, pronator teres, palmaris longus, flexor carpi ulnaris] [Second layer: flexor digitorum superficialis] [Third layer: flexor digitorum profundus, flexor pollicis longus]

Question 2

What is the common origin of the first layer of the anterior compartment of the forearm?

Answer 2

O: Medial epicondyle

Question 3

What is the insertion and action of flexor carpi radialis?

Answer 3

I: metacarpals II and III |A: flexion of the wrist joint and radial deviation (abduction)

Question 4

What is the insertion and action of pronator teres?

Answer 4

I: Shaft of the radius | A: Pronation of the forearm

Question 5

What is the insertion and action of palmaris longus?

Answer 5

I: Palmar aponeurosis |A: Weak wrist flexion

Question 6

What is the insertion and action of flexor carpi ulnaris?

Answer 6

I: Pisiform, hamate and metacarpal V | A: Flexion of the wrist and ulnar deviation (adduction)

Question 7

What is the origin, insertion, and action of flexor digitorum superficialis?

Answer 7

O: Medial epicondyle and proximal 1/3 of the radius | I: Middle phalanx of digits II to V | A: Flexion of the wrist, MCP and PIP joints.

Question 8

What is the origin, insertion and action of flexor digitorum profundus?

Answer 8

O: Proximal ulna and interosseus membrane | I: Distal phalanx of digits II to V | A: Flexion of the wrist, MCP, PIP and DIP joints.

Question 9

What is the origin, insertion and action of flexor pollicis longus?

Answer 9

O: Proximal radius and interosseus membrane | I: Distal phalanx of digit I | A: Flexion of the wrist and digit I.

Question 10

What are the muscles of the posterior compartment of the forearm?

Answer 10

[First layer: Anconeus, Brachioradialis, Extensor carpi radius longus and brevis, extensor digitorum, Extensor carpi ulnaris and extensor digiti minimi] [deep layer: abductor pollicis longus, extensor pollicis longus, extensor pollicis brevis, extensor indicis and supinator]

Question 11

What is the origin, insertion and action of brachioradialis?

Answer 11

O: Lateral supracondylar ridge | I: Styloid process | A: Flexion of the forearm (in neutral position)

Question 12

What is the origin, insertion and action of extensor carpi longus and brevis?

Answer 12

O: Lateral supracondylar ridge | I: Metacarpal II and III respectively| A: Extension and abduction of the hand at the wrist joint.

Question 13

What is the origin, insertion and action of extensor digitorum?

Answer 13

O: Lateral epicondyle | I: extensor expansion hood of digits II to V | A: extension of wrist, MCP, PIP and DIP joints

Question 14

What is the origin, insertion and action of extensor carpi ulnaris?

Answer 14

O: Lateral epicondyle | I: base of metacarpal V | A: Extension and adduction of the wrist joint.

Question 15

What is the origin, insertion and action of extensor digiti minimi?

Answer 15

O: Lateral epicondyle | I: extensor expansion hood of digit V | A: Accessory extension of digit V

Question 16

What is the common origin of the deep layer of the forearm?

Answer 16

O: Posterolateral ulna and interosseus membrane

Question 17

What is the insertion and action of abductor pollicis longus?

Answer 17

I: Base of metacarpal I | A: abduction of the thumb

Question 18

What is the insertion and action of extensor pollicis longus and brevis?

Answer 18

I: distal phalanx (longus) and proximal phalanx (brevis) | A: extension of the thumb

Question 19

What is the insertion and action of extensor indicis?

Answer 19

I: distal phalanx of digit II | A: accessory extension of digit II

Question 20

What is the origin, insertion and action of supinator?

Answer 20

O: Lateral epicondyle | I: proximal radius | A: supination of the forearm