Muscles of forearm & hand

Question 1

Extensor Carpi Radialis
Longus and Brevis

Answer 1

O: Common extensor origin-
lateral epicondyle of the humerus

I: Base of 2nd metacarpal (ECRL),
Base of 3rd metacarpals (ECRB)

A: Wrist extension and Radial Deviation

I: Radial n.

Question 2

Extensor Digitorum

Answer 2

O: Common extensor origin-
lateral epicondyle of the humerus

I: By four tendons, each to the base of
the extensor mechanism and to the
dorsal base of the proximal phalanx
of the fingers

A: Extends the MCP joints, extends the
IP joints of the second through fifth
digits

I: Radial n.

Question 3

Extensor Digiti Minimi

Answer 3

O: Ulnar side of the belly of the
extensor digitorum

I: Tendon usually divides, joining the
ulnar side of the tendon of the
extensor digitorum

A: Extends the MCP joints, extends the
IP joints of the little finger

I: Radial n.

Question 4

Extensor Carpi
Ulnaris

Answer 4

O: Common extensor origin-
lateral epicondyle of the humerus

I: Base of 5th metacarpal

A: Extension of wrist and ulnar deviation

I: Radial n.

Question 5

Abductor Pollicis
Longus

Answer 5

O: Posterior surface of the
middle part of the radius
and ulna, and adjacent
interosseous membrane

I: Base of 1st metacarpal

A: 1st digit ABD and extension at CMC joint

I: Radial n.

Question 6

Extensor Pollicis
Brevis

Answer 6

O: Posterior surface of the
middle to distal parts of the
radius and adjacent interosseous membrane

I: Proximal phalanx of thumb

A: 1st digit extension at MCP, IP joints

I: Radial n.

Question 7

Extensor Pollicis
Longus

Answer 7

O: Posterior surface of the
middle part of the ulna and
adjacent interosseous
membrane

I: Distal phalanx of thumb

A: 1st digit extension at MCP, IP joints

I: Radial n.

Question 8

Extensor Indicis

Answer 8

O: Posterior surface of the
middle to distal part of the
ulna and adjacent
interosseous membrane

I: Tendon blends with the ulnar side of
the index tendon of the extensor
digitorum

A: 2nd digit extension and wrist
extension

I: Radial n.

Question 9

Supinator

Answer 9

O: Lateral epicondyle of the
humerus and supinator
crest of the ulna

I: Lateral surface of the proximal
radius

A: Supination of forearm

I: Radial n.

Question 10

Pronator Teres

Answer 10

O: Humeral head: medial epicondyle
Ulnar head: medial to the tuberosity of ulna

I: Lateral surface of the middle radius

A: Pronation of forearm, elbow flexion

I: Median n.

Question 11

Flexor Carpi Radialis

Answer 11

O: Common flexor origin-
medial epicondyle of the humerus

I: 2nd and 3rd metacarpals

A: Wrist flexion, Radial deviation

I: Median n.

Question 12

Palmaris Longus

Answer 12

O: Common flexor origin-
medial epicondyle of the humerus

I: Common flexor origin-
medial epicondyle of the humerus

A: Flexion of wrist

I: Median n.

Question 13

Flexor Carpi Ulnaris

Answer 13

O: Humeral head: Common
flexor origin- medial
epicondyle of the humerus
Ulnar head: posterior border
of the middle one third of
the ulna

I: Pisiform bone, pisohamate and
pisometacarpal ligaments, and
palmar base of the fifth metacarpal
bone

A: Wrist flexion, Ulnar Deviation

I: Ulnar n.

Question 14

Flexor Digitorum
Superficialis

Answer 14

O: Humeroulnar head:
common flexor origin, and
the medial side of coronoid
process of the ulna
Radial head: oblique line
just distal and lateral to the bicipital tuberosity

I: By four tendons, each to the sides
of the middle phalanges of the
fingers

A: Flexion of PIP joint of fingers

I: Median n.

Question 15

Flexor Pollicis Longus

Answer 15

O: Middle part of the anterior
surface of the radius and
adjacent interosseous
membrane

I: Distal phalanx of thumb

A: Flexion of distal phalanx of thumb

I: Median n.

Question 16

Flexor Digitorum
Profundus

Answer 16

O: Proximal 3/4 of the medial
side of the ulna and
adjacent interosseous
membrane

I: By four tendons, each to the palmar
base of the distal phalanges of the
fingers

A: Flex wrist, flex all joints to DIP in
digits 2-5

I: Medial half: ulnar nerve
Lateral half: median nerve

Question 17

Pronator Quadratus

Answer 17

O: Anterior surface of distal ulna

I: Anterior surface of distal radius

A: Pronates forearm

I: Median n.

Question 18

Abductor Pollicis
Brevis

Answer 18

O: Palmar tubercles of the
trapezium and scaphoid

I: Base of proximal phalanx of thumb

A: Abduction of thumb at MCP, CMC joint

I: Median n.

Question 19

Flexor Pollicis Brevis

Answer 19

O: Transverse carpal ligament
and palmar tubercle of trapezium

I: Radial side of proximal phalanx of
thumb

A: Flexion of thumb

I: Median n.

Question 20

Opponens Pollicis

Answer 20

O: Transverse carpal ligament
and palmar tubercle of trapezium

I: Shaft of the thumb metacarpal

A: Opposition of thumb

I: Median n.

Question 21

Adductor Pollicis

Answer 21

O: Oblique head: capitate
bone& base of second and
third metacarpal
Transverse head: palmar
surface of 3rd metacarpal

I: Ulnar side of the base of the
proximal phalanx of the thumb

A: Adduction of thumb

I: Ulnar n.

Question 22

Abductor Digiti Minimi

Answer 22

O: Pisiform bone, and tendon
of the flexor carpi ulnaris

I: Base of the proximal phalanx of the
little finger

A: Abduction of the little finger at MCP joint

I: Ulnar n.

Question 23

Flexor Digiti Minimi

Answer 23

O: Hook of the hamate

I: base of the proximal phalanx of the little finger

A: Flexion of little finger

I: Ulnar n.

Question 24

Opponens Digiti
Minimi

Answer 24

O: Transverse carpal ligament
& hook of the hamate

I: Shaft of the fifth metacarpal

A: Flexion of 5th metacarpal, lateral
rotation producing opposition

I: Ulnar n.

Question 25

Lumbricals of the hand First and second:

Answer 25

O: Radial surface of the flexor profundus tendons of the index and middle fingers, respectively I: Into the radial border of the extensor expansion on the dorsum of the respective digits A: Flexion at MCP, Extension at IP I: Medial two: ulnar nerve

Question 26

Lumbricals of the hand Third and fourth:

Answer 26

O: Third: Adjacent sides of the flexor profundus tendons of the middle and ring fingers. Fourth: Adjacent sides of the flexor profundus tendons of the ring and little fingers I: Into the radial border of the extensor expansion on the dorsum of the respective digits A: Flexion at MCP, Extension at IP I: Lateral two: median nerve

Question 27

Dorsal Interossei Third and fourth:

Answer 27

O: Third: adjacent sides of the third and fourth metacarpal Fourth: adjacent sides of the fourth and fifth metacarpal I: Third: Ulnar side of the middle finger, chiefly into extensor expansion Fourth: Ulnar side of the ring finger A: Abduction of 2nd, 3rd, 4th digits away from middle finger I: Ulnar n.

Question 27

Dorsal Interossei First and second:

Answer 27

O: First: adjacent sides of the first and second metacarpal Second: adjacent sides of the second and third metacarpal I: First: Radial side of the index finger, chiefly to the base of the proximal phalanx Second: Radial side of the middle finger A: Abduction of 2nd, 3rd, 4th digits away from middle finger I: Ulnar n.

Question 28

Palmar Interossei First and second:

Answer 28

O: First: ulnar side of the thumb metacarpal Second: ulnar side of the second metacarpal I: First: Ulnar side of the thumb. Second: Ulnar side of the index finger A: Adduction of 2nd, 4th, 5th digits towards middle finger, flexion of digit at MCP, extension at IP I: Ulnar n.

Question 29

Palmar Interossei Third and fourth:

Answer 29

O: Third: radial side of the fourth metacarpal Fourth: radial side of the fifth metacarpal I: Third: Radial side of the ring finger Fourth: Radial side of the little finger A: Adduction of 2nd, 4th, 5th digits towards middle finger, flexion of digit at MCP, extension at IP I: Ulnar n.