Dorsal Forearm and Dorsum of the Hand

Question 1

Brachioradialis Origin

Answer 1

Proximal ⅔ of the lateral supraepicondylar ridge of the humerus

Question 2

Brachioradialis Insertion

Answer 2

Lateral surface of distal end of radius proximal to styloid process

Question 3

Brachioradialis Action

Answer 3

Weak flexion of elbow, maximal when forearm is in midpronated position

Question 4

Brachioradialis Innervation

Answer 4

Radial nerve C5, C6, C7

Question 5

Extensor carpi radialis longus Origin

Answer 5

Origin:Lateral supra-epicondylar ridge of the humerus

Question 6

Extensor carpi radialis longus Insertion

Answer 6

Insertion: Dorsal aspect of base of 2nd metacarpal

Question 7

Extensor carpi radialis longus Action

Answer 7

Action: Extend and abduct wrist joint

Question 8

Extensor carpi radialis longus Innervation

Answer 8

Innervation: Radial nerve C6, C7

Question 9

Extensor carpi radialis brevis Origin

Answer 9

Origin: Lateral epicondyle of humerus

Question 10

Extensor carpi radialis brevis Insertion

Answer 10

Insertion: Dorsal aspect of base of 3rd metacarpal

Question 11

Extensor carpi radialis brevis Action

Answer 11

Action: Extend and abduct wrist joint, active during fist clenching

Question 12

Extensor carpi radialis brevis Innervation

Answer 12

Innervation: Deep branch of radial nerve C7, C8

Question 13

Extensor digitorum Origin

Answer 13

Origin: Lateral epicondyle of the humerus

Question 14

Extensor digitorum Insertion

Answer 14

Insertion: Extensor expansions of medial four fingers

Question 15

Extensor digitorum Action

Answer 15

Action: Extends wrist joint, extends medial four fingers primarily at metacarpophalangeal joints, secondarily at IP joints

Question 16

Extensor digitorum Innervation

Answer 16

Innervation Deep branch of radial nerve C7, C8

Question 17

Extensor digiti minimi Origin

Answer 17

Origin: Lateral epicondyle of humerus

Question 18

Extensor digiti minimi Insertion

Answer 18

Insertion: Extensor expansion of 5th finger

Question 19

Extensor digiti minimi Action

Answer 19

Action: Extends wrist joint, extends 5th finger at metacarpophalangeal joint, secondarily at IP joint

Question 20

Extensor digiti minimi Inervation

Answer 20

Innervation Posterior interosseous nerve C7. C8 continuation of deep branch of radial nerve.

Question 21

Extensor carpi ulnaris Origin

Answer 21

Origin: Lateral epicondyle of humerus, posterior border of ulna via a shared aponeurosis

Question 22

Extensor carpi ulnaris Insertion

Answer 22

Insertion: Dorsal aspect of base of 5th metacarpal

Question 23

Extensor carpi ulnaris Action

Answer 23

Action: extends and adducts wrist joint, active during fist clenching

Question 24

Extensor carpi ulnaris Innervation

Answer 24

Innervation: Posterior interosseous nerve C7 C8 continuation of deep branch of radial nerve

Question 25

Supinator Origin

Answer 25

Origin: Lateral epicondyle of humerus, radial collateral and annular ligaments, supinator fossa, crest of ulna

Question 26

Supinator Insertion

Answer 26

Insertion: Lateral posterior, anterior surfaces of proximal third of radius

Question 27

Supinator Action

Answer 27

Action: Supinates forearm, rotates radius to turn palm anteriorly or superiorly if elbow is flexed

Question 28

Supinator Innervation

Answer 28

Innervation: Deep branch of radial nerve C7 C8

Question 29

Abductor pollicis longus Origin

Answer 29

Origin: Posterior surface of proximal halves of ulna, radius, and interosseous membrane

Question 30

Abductor pollicis longus Insertion

Answer 30

Insertion: base of 1st metacarpal

Question 31

Abductor pollicis longus Action

Answer 31

Action: Extends wrist joint, abducts thumb and extends it at carpometacarpal joint

Question 32

Abductor pollicis longus Innervation

Answer 32

Innervation: Posterior interosseous nerve C7, C8, continuation of deep branch of radial nerve

Question 33

Extensor pollicis longus Origin

Answer 33

Origin: Posterior surface of middle third of ulna and interosseous membrane

Question 34

Extensor pollicis longus Insertion

Answer 34

Insertion: Dorsal aspect of base of distal phalanx of thumb

Question 35

Extensor pollicis longus Action

Answer 35

Action: extends wrist joint, extends distal phalnx of thumb at IP joint, extends metacarpophalangeal and carpometacarpal joints

Question 36

Extensor pollicis longus Innervation

Answer 36

Innervation: Posterior interosseous nerve C7, C8, continuation of deep branch of radial nerve

Question 37

Extensor pollicis brevis Origin

Answer 37

Origin: Posterior surface of distal third of radius and interosseous membrane

Question 38

Extensor pollicis brevis Insertion

Answer 38

Insertion: Dorsal aspect of base of proximal phalanx of thumb

Question 39

Extensor pollicis brevis Action

Answer 39

Action: Extends wrist joint, extends proximal phalanx of thumb at metacarpophalangeal joint, extends carpometacarpal joint

Question 40

Extensor pollicis brevis Innervation

Answer 40

Innervation: Posterior interosseous nerve C7, C8, continuation of deep branch of radial nerve

Question 41

Extensor indicis Origin

Answer 41

Origin: Posterior surface of distal third of ulna and interosseous membrane

Question 42

Extensor indicis Insertion

Answer 42

Insertion: Extensor expansion of 2nd finger

Question 43

Extensor indicis Action

Answer 43

Action: Extends wrist joint, extends 2nd finger, helps extend hand at wrist

Question 44

Extensor indicis Innervation

Answer 44

Innervation: Posterior interosseous nerve C7, C8, continuation of deep branch of radial nerve