The anatomy of the hand

Question 1

Where do all fingers point when they’re flexed?

Answer 1

Scaphoid tubercle

Question 2

What do ligaments in the hand do?

Answer 2

Join bones to other bones

Question 3

Characteristics of ligaments in hands

Answer 3

Co-axial or co-lateral

Question 4

Features of hand

Answer 4

• Creases
• Thenar/hypothenar eminence
• Hills and valleys
• Web spaces
• Sesamoids
• Lister’s tubercle - extensor polices longus
• DIP - distal interphalangeal joint
• PIP - proximal interphalangeal joint
• MCP - metacarpophalangeal joint

Question 5

How many bones are in the hand?

Answer 5

31

Question 6

Where are the 31 bones in the hand?

Answer 6

• Phalanges: 14
• Sesamoids: 2
• Metacarpals: 5
• Carpals (proximal row): 4
• Carpals (distal row): 4
• Radius
• Ulna

Question 7

What are the 8 bones in the hand?

Answer 7

• Scaphoid
• Lunate
• Triquetrum
• Pisiform
• Trapezium
• Trapezoid
• Capitate
• Hamate

Question 8

How do you assess the hand?

Answer 8

To assess the hand, palpate for swelling/tenderness. The following areas should be palpated:
- Radial styloid
- Scaphoid
- 1st MC/trapezium joint
- Lunate
- Lister’s tubercle
Then assess for symmetry and look for any visible fractures and any phalangeal rotation. Normally, everything in the hand should form a line from fingertip to wrist

Question 9

What does FOOSH stand for?

Answer 9

Fall on outstretched hand

Question 10

Symptoms of FOOSH injury

Answer 10

• Tender snuffbox
• Painful/swollen wrist
• High frequency of non-union and avascular necrosis

Question 11

Which parts of the hand can be palpated on the central and ulnar sides?

Answer 11

• Metacarpals
• Ulnar styloid
• Triquetrum
• Pisiform
• Hook of hamate

Question 12

Characteristics of injured pisiform/hamate

Answer 12

• Frequently misdiagnosed as tendonitis/spasm
• Pain/swelling over hypothenar eminence
• Painful gripping and swinging

Question 13

Range of wrist motion

Answer 13

• Flexion (make fist)
• Extension (extend fingertips)
• Radial deviation
• Ulnar deviation (typically greater than radial deviation)

Question 14

Range of finger motion:

Answer 14

• Flexion/extension at MCP, PIP, DIP
• Tight wrist and open to test grip
• Abduction/adduction at MCP (spread fingers apart then back together)

Question 15

Where are proximal phalanges frequently injured?

Answer 15

Shaft/base

Question 16

When are metacarpals frequently injured?

Answer 16

Boxing

Question 17

What are intrinsic hand muscles?

Answer 17

Start in metacarpals and finish at fingertips

Question 18

What are extrinsic hand muscles?

Answer 18

Start in wrists and finish at fingertips

Question 19

How many extensor muscles are there?

Answer 19

12

Question 20

How many flexor muscles are there?

Answer 20

8

Question 21

How many intrinsics are there?

Answer 21

2 sets of 4

Question 22

Which nerve supplies extensor muscles?

Answer 22

Radial nerve

Question 23

What is the common extensor origin?

Answer 23

Lateral epicondyle

Question 24

Which condition affects the common extensor origin?

Answer 24

Tennis elbow

Question 25

What are the 12 extensor muscles?

Answer 25

- Brachioradialis - from brachium to radius - Extensor carpi radialis longus - Extensor carpus radius brevis - Abductor pollicis longus - Extensor pollicis brevis - Extensor pollicis longus - Extensor indices proprius - Extensor digitorum communis - Extensor digitorum minimi - Supinator - Anconeus - Extensor carpi ulnaris

Question 26

What are the two types of flexors?

Answer 26

Superficialis and deepus

Question 27

Which nerves supply the flexor muscles?

Answer 27

Median and ulnar

Question 28

Which arteries supply the flexor muscles?

Answer 28

Radial and ulnar

Question 29

Which joint do the superficial flexor muscles bend?

Answer 29

The PIP joint

Question 30

Which joint do the deep flexor muscles bend?

Answer 30

DIP joint

Question 31

What is the common flexor origin?

Answer 31

Medial epicondyle

Question 32

Which condition affects the common flexor origin?

Answer 32

Golfer's elbow

Question 33

Are the 8 flexor muscles posterior or anterior?

Answer 33

Anterior

Question 34

What is the name of the vessel that transports nerves/arteries/flexor tendons into the hand?

Answer 34

Palmar tunnels

Question 35

How many palmar tunnels are there?

Answer 35

2

Question 36

What are the 8 flexor muscles?

Answer 36

- Flexor digitorum superficialis (middle finger) - Flexor digitorum profundus - Palmaris longus - Flexor pollicis longus (thumb) - Flexor carpi radialis (index fingers) - Flexor carpi ulnaris - Pronator teres (in thumb) - Pronator quadratus

Question 37

How to test the FDS?

Answer 37

Flex the finger at the PIP joint - FDS is the only tendon functioning here

Question 38

How to test the FDP?

Answer 38

Flex the DIP joint - FDP is the only tendon functioning here

Question 39

Function of transport extensor tendons?

Answer 39

Reduce bowstringing in transition from forearm into hand

Question 40

How many compartments does the extensor retinaculum form?

Answer 40

6

Question 41

Why are tendons bathed in synovial fluid?

Answer 41

Blood flow

Question 42

What are vinaculae?

Answer 42

Blood vessels supplying tendons

Question 43

What are palmar spaces involved in?

Answer 43

Infection

Question 44

Which two spaces are known for collecting bacteria and pus?

Answer 44

Thenar and midpalmar

Question 45

What is the palmar aponeurosis?

Answer 45

A sheet of tissue under the skin of the palm that helps to form ridges

Question 46

What 4 deep spaces are involved in hand infections?

Answer 46

Subfascial palmar Dorsal subaponeurotic Thenar Midpalmar

Question 47

What are the two eminences in the finger?

Answer 47

Thenar and hypothenar

Question 48

Characteristics of the thenar eminence

Answer 48

3 muscles of the thumb, atrophy seen in carpal tunnel syndrome median nerve

Question 49

Characteristics of hypothenar eminence

Answer 49

3 muscles of little finger, atrophy with ulnar nerve compression

Question 50

What are the three muscles found in an eminence?

Answer 50

Opponens (helps thumb oppose) Abductor (lift away from palm) Flexor (flex thumb down)

Question 51

What is Dupuytren's contracture?

Answer 51

Contracture under skin but above tendons

Question 52

Which tunnel holds the median nerve?

Answer 52

Carpal tunnel

Question 53

Which vessel holds the ulnar nerve and artery?

Answer 53

Guyon's canal

Question 54

Test for radial nerve

Answer 54

Thumb up/ little and index fingers up

Question 55

Test for ulnar nerve

Answer 55

Cross fingers

Question 56

Test for median nerve

Answer 56

Okay sign

Question 57

What happens when ulnar nerve is damaged?

Answer 57

Flattening of hypothenar eminence and loss of intrinsics (can't PAD or DAB)

Question 58

What does DAB stand for?

Answer 58

Dorsal abducts

Question 59

What does PAD stand for?

Answer 59

Palm adducts

Question 60

Where are interossei found?

Answer 60

Between metacarpals, there are two layers (one on dorsal and one on palmar side)

Question 61

Which nerve causes adduction and abduction of fingers?

Answer 61

Ulnar nerve

Question 62

What connects flexors to fingers?

Answer 62

Flexor retinaculum

Question 63

Characteristics of carpal tunnel

Answer 63

U-shaped bones with lid, joining scaphoid/pisiform/hamate

Question 64

Opposition of thumb

Answer 64

Touch tip to tip of each finger

Question 65

Flexion of thumb

Answer 65

Moves towards palm

Question 66

Extension of thumb

Answer 66

Away from palm

Question 67

Where does most movement in the digits occur?

Answer 67

Carpometacarpal joint

Question 68

Where does flexion/extension of the thumb occur?

Answer 68

MCP and IP