Posterior Forearm Muscles

Question 1

What is the MA of the Extensor Carpi Radialis Longus and Brevis (ECRL & ECRB)?

Answer 1

Extension and radial deviation of the wrist (radiocarpal joint)

ECRL active during fist clenching

Question 2

What is the PA of the Extensor Carpi Radialis Longus and Brevis (ECRL & ECRB)?

Answer 2

ECRL: lateral supra-epicondylar ridge of humerus

ECRB: lateral epicondyle of humerus (common extensor tendon)

Question 3

What is the DA of the Extensor Carpi Radialis Longus and Brevis (ECRL & ECRB)?

Answer 3

ECRL: base of 2nd metacarpal

ECRB: base of 3rd metacarpal

Question 4

What is the N for the Extensor Carpi Radialis Longus and Brevis (ECRL & ECRB)?

Answer 4

Radial nerve (C6, C7, & C8)

Question 5

What is the MA of the Extensor Digitorum (ED)?

Answer 5

Extension of the medial 4 digits (no thumb) at the metacarpophalangeal joint (1) and interphalangeal joints (2)

Question 6

What is the PA of the Extensor Digitorum (ED)?

Answer 6

Lateral epicondyle of the humerus (common extensor tendon)

Question 7

What is the DA of the Extensor Digitorum (ED)?

Answer 7

Extensor expansions of medial 4 digits

Question 8

What is the N for the Extensor Digitorum (ED)?

Answer 8

Radial nerve (C7 & C8)

Question 9

What is the MA of the Extensor Digiti Minimi (EDM)?

Answer 9

Extension of the 5th digit (pinky) at metacarpophalangeal joint (1) and interphalangeal joints (2)

Question 10

What is the PA of the Extensor Digiti Minimi (EDM)?

Answer 10

Lateral epicondyle of humerus (common extensor origin)

Question 11

What is the DA of the Extensor Digiti Minimi (EDM)?

Answer 11

Extensor expansion of 5th digit

Question 12

What is the N for the Extensor Digiti Minimi (EDM)?

Answer 12

Radial nerve (C7 & C8)

Question 13

What is the MA of the Extensor Carpi Ulnaris (ECU)?

Answer 13

Extension and ulnar deviation of the wrist (radiocarpal joint)

Active during fist clenching

Question 14

What is the PA of the Extensor Carpi Ulnaris (ECU)?

Answer 14

Lateral epicondyle of humerus (common extensor tendon)

Question 15

What is the DA of the Extensor Carpi Ulnaris (ECU)?

Answer 15

Base of 5th metacarpal

Question 16

What is the N for the Extensor Carpi Ulnaris (ECU)?

Answer 16

Radial nerve (C7 & C8)

Question 17

What is the MA of the Supinator?

Answer 17

Supination of the forearm (radioulnar joint)

Question 18

What is the PA of the Supinator?

Answer 18

Lateral epicondyle of humerus, radial collateral ligament, and annular ligament

Question 19

What is the DA of the Supinator?

Answer 19

Lateral radius

Question 20

What is the N for the Supinator?

Answer 20

Radial nerve (Posterior Interosseous Nerve) (C7 & C8)

Question 21

What is the MA of the Extensor Indicis (EI)?

Answer 21

Extension of the 2nd digit at the metacarpophalangeal joint

May assist with wrist extension (radiocarpal joint)

Question 22

What is the PA of the Extensor Indicis (EI)?

Answer 22

Posterior ulna and interosseous membrane

Question 23

What is the DA of the Extensor Indicis (EI)?

Answer 23

Extensor expansion of 2nd digit

Question 24

What is the N for the Extensor Indicis (EI)?

Answer 24

Radial nerve (Posterior Interosseous Nerve) (C7 & C8)

Question 25

What is the MA of the Abductor Pollicis Longus (APL)?

Answer 25

Radial abduction and extension of the thumb at the carpometacarpal joint

Question 26

What is the PA of the Abductor Pollicis Longus (APL)?

Answer 26

Posterior surface of: ulna radius interosseous membrane

Question 27

What is the DA of the Abductor Pollicis Longus (APL)?

Answer 27

Base of 1st metacarpal

Question 28

What is the N for the Abductor Pollicis Longus (APL)?

Answer 28

Radial nerve (Posterior Interosseous Nerve) (C7 & C8)

Question 29

What is the MA of the Extensor Pollicis Longus and Brevis (EPL & EPB)?

Answer 29

Extension of the thumb at the metacarpophalangeal and carpometacarpal joints EPL does extension of the thumb at the interphalangeal joint

Question 30

What is the PA of the Extensor Pollicis Longus and Brevis (EPL & EPB)?

Answer 30

EPL: posterior ulna and interosseous membrane EPB: posterior radius and interosseous membrane

Question 31

What is the DA of the Extensor Pollicis Longus and Brevis (EPL & EPB)?

Answer 31

EPL: base of distal phalanx of thumb (including thumb nail) EPB: base of proximal phalanx of thumb (not including thumb nail)

Question 32

What is the N for the Extensor Pollicis Longus and Brevis (EPL & EPB)?

Answer 32

Radial nerve (Posterior Interosseous Nerve) (C7 & C8)