Wrist and Hand

Question 1

Flexor Digitorum Profundus:

O: ant & med surface of proximal ¾ of ulna, interosseous membrane

I: by four tendons into base of the distal phalanges(n) – ant surface

A: flexes distal interphalangeal joints of 2-5, flexes proximal interphalangeal and metacarpophalangeal(adj) joints, flexion of wrist

N: 1-2 digits: median nerve (C7, C8, T1) ( 2,3)
N: 3-4 digits: ulnar nerve (C7, C8, T1) (4,5)

Answer 1

Muscle Testing - Flexor Digitorum Profundus:

Patient: sitting or supine
Fixation: wrist in slight extension, examiner stabilizes the proximal and middle phalanges
Test: flexion of distal interphalangeal joint of 2-5 digits, each finger tested
Pressure: against the palmar surface of the distal phalanx

Question 2

Pronator Quadratus:

O: medial side, anterior surface of distal ¼ of ulna

I: lateral side, anterior surface of the distal ¼ of radius

A: pronates the forearm

N: median nerve (C7, C8, T1)

Answer 2

Muscle Testing - Pronator Quadratus:

Patient: supine or sitting
Fixation: elbow held against patient’s side
Test: pronation of forearm, with elbow completely flexed
Pressure: at the lower forearm, above the wrist

Question 3

Extensor Pollicis Longus:

O: middle 1/3 of posterior surface of ulna, distal to origin of abductor pollicis longus, interosseous membraneI: base of distal phalanx of the thumb, dorsal surface

A: extends IP, aids extension of MCP & CMC of thumb, aids abduction & extension of wrist

N: radial nerve (C6, C7, C8)

Answer 3

Muscle Testing - Extensor Pollicis Longus:

Patient: sitting or supine
Fixation: examiner stabilizes the hand and gives counter-pressure against the palmar surface of the first metacarpal and proximal phalanx
Test: extension of the interphalangeal joint of the thumb
Pressure: against the distal/dorsal surface of the interphalangeal joint of the thumb
NOTE: See Kendall Page 266

Question 4

Extensor Pollicis Brevis:

O: posterior surface of body of radius distal to origin of abductor pollicis longus & interosseous membrane

I: base of the proximal phalanx of the thumb, dorsal surface

A: extends MCP of thumb, extends & abducts CMC joint, aids in abduction of wrist. (say full name not short writing)

N: radial nerve (C6, C7, C8)

Answer 4

Muscle Testing - Extensor Pollicis Brevis:

Patient: sitting or supine
Fixation: the examiner stabilizes the wrist
Test: extension of the metacarpophalangeal joint of the thumb
Pressure: against the proximal/dorsal surface of the proximal phalanx

Question 5

Abductor Pollicis Longus:

O: posterior surface of body of ulna, distal to origin of supinator, interosseous membrane, poster surface of middle 1/3 of body of radius

I: base of the first metacarpal bone, radial side

A: abducts & extends CMC of thumb, abducts and flexes the wrist

N: radial nerve (C6, C7, C8)

Answer 5

Muscle Testing - Abductor Pollicis Longus:

Patient: sitting or supine
Fixation: examiner stabilizes the wrist
Test: abduction and slight extension of the first metacarpal bone
Pressure: against the lateral surface of the distal end of the first metacarpal

Question 6

Extensor Indicis:

O: posterior surface of body of ulna, distal to origin of extensor pollicis longus & interosseous membrane

I: into extensor expansion of index finger with extensor digitorum longus tendon

A: extends the MCP & IP of index finger

N: radial nerve (C6, C7, C8)

Question 7

Muscles of the Hand:
Thenar Muscles:

Abductor Pollicis Brevis:

O: flexor retinaculum, tubercle of the trapezium bone and tubercle of the scaphoid bone

I: Base of the proximal phalanx of the thumb, radial side and extensor expansion (attacht to this will have extend the interphalangeal)

A: abducts carpometacarpal and metacarpophalangeal joints of the thumb, extends the interphalangeal joint of the thumb, assists in opposition

N: median nerve (C6, C7, C8, T1)

Answer 7

Question 8

Muscles of the Hand: Thenar Muscles:
Opponens Pollicis:

O: Flexor retinaculum and tubercle of the trapezium bone

I: entire length of the first metacarpal bone, radial side

A: opposes the carpometacarpal joint of the thumb (flexion, abduction, medial rotation)

N: median nerve (C6, C7, C8, T1)

Answer 8

Question 9

Muscles of the Hand: Thenar Muscles:

Flexor Pollicis Brevis (sesamoid bone)

O: Superficial head: flexor retinaculum & trapezium bone
O: Deep head: trapezoid & capitate bones

I: base of the proximal phalanx of thumb,

A: flexes metacarpophalangeal and carpometacarpal joints, opposition of thumb,

N: Superficial head: median nerve (C6, C7, C8, T1)
N: Deep head: ulnar nerve (C8, T1) easy to forget

Answer 9

Question 10

Muscles of the Hand: Thenar Muscles:

Adductor Pollicis:

O: Oblique fibres: capitate bone and bases of the 2nd to 3rd metacarpal bones
O: Transverse fibres: palmar surface of the 3rd metacarpal bone

I: Oblique fibres: extensor expansion
I: Transverse fibres: ulnar side of base of the proximal phalanx of the thumb

A: adducts carpometacarpal joint, and adducts and assists flexion in metacarpophalangeal joint, aids in opposition

N: ulnar nerve (C8, T1) (easy get mess up because it’s on the radial side but ulnar nerve)

Answer 10

Question 11

Muscles of the Hand - Hypothenar Muscles:

Abductor Digiti Minimi:

O: tendon of the flexor carpi ulnaris and the pisiform bone

I: a) base of proximal phalanx of little finger, ulnar side (mainly palpate here)
I: b)ulnar border of the extensor expansion

A: abducts, assists in opposition, assists flexion at metacarpophalangeal joint of little finger.

N: ulnar nerve (C7, C8, T1)

Answer 11

Question 12

Muscles of the Hand Hypothenar Muscles:

Flexor Digiti Minimi Brevis:
(in Kendall no brevis in name of muscle)

O: hook of the hamate bone and the flexor retinaculum

I: base of the proximal phalanx of the little finger, ulnar side

A: flexes the metacarpophalangeal joint of the little finger and aids in opposition of the little finger toward the thumb

N: ulnar nerve (C7, C8, T1)

Answer 12

Question 13

Muscles of the Hand - Hypothenar Muscles:
Opponens Digiti Minimi:

O: hook of the hamate bone and the flexor retinaculum

I: entire length of the 5th metacarpal bone, ulnar side

A: opposes (flexion & slight rotation) carpometacarpal joint of the little finger

N: ulnar nerve (C7, C8, T1)

Answer 13

Question 14

Muscles of the Hand - Hypothenar Muscles:

Palmaris Brevis:

O: ulnar border of the palmar aponeurosis and palmar surface of the flexor retinaculum

I: skin on the ulnar border of the hand

A: corrugates the skin on the ulnar side of the hand

N: ulnar nerve (C7, C8, T1)

Question 15

Lumbricals:

O: flexor digitorum profundus tendon (start in the front)

I: radial border of the extensor expansion on dorsum of digit ( wrap around metacarpo to attact to the back of the of the finger)

A: extend the interphalangeal joint & flex the metacarpophalangeal joints simultaneously (2-5)

N: 1-2: median nerve (C6, C7, C8, T1) (finger 2,3)
N: 3-4: ulnar nerve (C7, C8, T1) (finger 4,5)

Answer 15

Question 16

Dorsal Interossei:

O: metacarpal bone

I: extensor expansion & to the base of the proximal phalanx 2,3,4

A: abducts index, middle & ring fingers, assists in flexion at the metacarpophalangeal joints & extension of the interphalangeal joints.

N: ulnar nerve (C8, T1)

Answer 16

Question 17

Palmar Interossei:

O: metacarpal bone

I: extensor expansion

A: (adduct the thumb), index, ring and little finger, aids flexion of metacarpophalangeal joints and extension of the interphalangeal joints

N: ulnar nerve (C8, T1)

Answer 17