Chapter 7 Wrist and Hand Joint Extrinsic Muscles

Question 1

Flexor Carpi Radialis O&I

Answer 1

origin: medial epicondyle of humerus
insertion: base of 2nd and 3rd metacarpals on palmar surface

Question 2

Flexor Carpi Radialis Action

Answer 2

flexion of wrist, abduction of wrist, weak flexion of elbow, weak pronation of forearm

Question 3

Flexor Carpi Radialis Innervation

Answer 3

median nerve (C6, C7)

Question 4

Palmaris Longus O&I

Answer 4

origin: medial epicondyle of humerus
insertion: palmar aponeurosis of the 2nd, 3rd, 4th, 5th, metacarpals

Question 5

Palmaris Longus Action

Answer 5

flexion of the wrist, weak flexion of the elbow

Question 6

Palmaris Longus Innervation

Answer 6

median nerve (C6, C7)

Question 7

Flexor Carpi Ulnaris O&I

Answer 7

origin: medial epicondyle of humerus and posterior aspect of proximal ulna
insertion: base of 5th metacarpal (palmar surface), pisiform, and hamate

Question 8

Flexor Carpi Ulnaris Action

Answer 8

flexion of wrist, adduction of wrist, weak flexion of the elbow

Question 9

Flexor Carpi Ulnaris Innervation

Answer 9

ulnar nerve (C8, T1)

Question 10

Flexor Digitorum Superficialis O&I

Answer 10

origin: medial epicondyle of humerus
ulnar head: medial coronoid process
radial head: upper 2/3 of anterior border of the radius just distal to the radial tuberosity
insertion: each tendon splits and attaches to the sides of the middle phalanx of the four fingers on the palmar surface

Question 11

Flexor Digitorum Superficialis Action

Answer 11

flexion of the fingers at the metacarpophalangeal and proximal interphalangeal joints, flexion of the wrist, weak flexion of the elbow

Question 12

Flexor Digitorum Superficialis Innervation

Answer 12

median nerve (C7, C8, T1)

Question 13

Flexor Digitorum Profundus O&I

Answer 13

origin: proximal 3/4 of anterior and medial ulna
insertion: base of distal phalanges of four fingers

Question 14

Flexor Digitorum Profundus Action

Answer 14

flexion of the four fingers at the metacarpophalageal, proximal interphalangeal, and distal interphalangeal joints, flexion of wrist

Question 15

Flexor Digitorum Profundus Innervation

Answer 15

median nerve (C8, T1) to 2nd and 3rd fingers , ulnar nerve (C8, T1) to 4th and 5th fingers

Question 16

Flexor Pollicis Longus O&I

Answer 16

origin: middle anterior surface of the radius and anterior medial border of the ulna just distal to the coronoid process
insertion: base of distal phalanx of thumb on palmar surface

Question 17

Flexor Pollicis Longus Action

Answer 17

flexion of the thumb carpometacarpal, metacarpophalangeal, and interphalangeal joints, flexion of wrist, abduction of wrist

Question 18

Flexor Pollicis Longus Innervation

Answer 18

median nerve palmar interosseous branch (C8, T1)

Question 19

Extensor Carpi Ulnaris O&I

Answer 19

origin: lateral epicondyle of humerus and middle 1/2 of the posterior border of the ulna
insertion: base of 5th metacarpal on dorsal surface

Question 20

Extensor Carpi Ulnaris Action

Answer 20

extension of wrist, adduction of wrist, weak extension of elbow

Question 21

Extensor Carpi Ulnaris Innervation

Answer 21

radial nerve (C6, C7, C8)

Question 22

Extensor Carpi Radialis Brevis O&I

Answer 22

origin: lateral epicondyle of humerus
insertion: base of 3rd metacarpal on dorsal surface

Question 23

Extensor Carpi Radialis Brevis Action

Answer 23

extension of wrist, abduction of wrist, weak flexion of elbow

Question 24

Extensor Carpi Radialis Brevis Innervation

Answer 24

radial nerve (C6, C7)

Question 25

Extensor Carpi Radialis Longus O&I

Answer 25

origin: distal third of the lateral supracondylar ridge of humerus and lateral epicondyle of the humerus insertion: base of 2nd metacarpal on dorsal surface

Question 26

Extensor Carpi Radialis Longus Action

Answer 26

extension of wrist, abduction of wrist, weak flexion of elbow, weak pronation

Question 27

Extensor Carpi Radialis Longus Innervation

Answer 27

radial nerve (C6, C7)

Question 28

Extensor Digitorum O&I

Answer 28

origin: lateral epicondyle of humerus insertion: four tendons to bases of middle and distal phalanxes of four fingers on dorsal surface

Question 29

Extensor Digitorum Action

Answer 29

extension of the 2nd, 3rd, 4th, and 5th phalanges at the metacarophalangeal joints, extension of wrist, weak extension of elbow

Question 30

Extensor Digitorum Innervation

Answer 30

radial nerve (C6, C7, C8)

Question 31

Extensor Indicis O&I

Answer 31

origin: middle to distal 1/3 of posterior ulna insertion: base of the middle and distal phalanxes of the 2nd phalange on dorsal surface

Question 32

Extensor Indicis Action

Answer 32

extension of the index finger at the MCP joint, weak wrist extension, weak supination

Question 33

Extensor Indicis Innervation

Answer 33

radial nerve (C6, C7, C8)

Question 34

Extensor Digiti Minimi O&I

Answer 34

origin: lateral epicondyle of humerus insertion: base of the middle and distal phalanxes of the 5th phalange on dorsal surface

Question 35

Extensor Digiti Minimi Action

Answer 35

extension of the little finger at the MCP joint

Question 36

Extensor Digiti Minimi Innervation

Answer 36

radial nerve (C6, C7, C8)

Question 37

Extensor Pollicis Longus O&I

Answer 37

origin: posterior lateral surface of the lower middle ulna insertion: base of distal phalanx of thumb on dorsal surface

Question 38

Extensor Pollicis Longus Action

Answer 38

extension of the thumb t the CMC, MCP, IP joints, extension of wrist, abduction of wrist, weak supination

Question 39

Extensor Pollicis Longus Innervation

Answer 39

radial nerve (C6, C7, C8)

Question 40

Extensor Pollicis Brevis O&I

Answer 40

origin: posterior surface of lower middle radius insertion: base of proximal phalanx of thumb on dorsal surface

Question 41

Extensor Pollicis Brevis Action

Answer 41

extension of the thumb at the CMC, MCP joints, weak wrist extension, abduction of the wrist

Question 42

Extensor Pollicis Brevis Innervation

Answer 42

radial nerve (C6, C7)

Question 43

Abductor Pollicis Longus O&I

Answer 43

origin: posterior aspect of radius and mid shaft of the ulna insertion: base of 1st metacarpal on dorsal lateral surface

Question 44

Abductor Pollicis Longus Action

Answer 44

abduction of the thumb at the CMC joint, abduction of wrist, extension of thumb at the CMC joint, weak wrist extension, weak supination

Question 45

Abductor Pollicis Longus Innervation

Answer 45

radial nerve (C6, C7)