Upper limb 1.5

Question 1

What is the origin of the adductor pollicis muscle?

Answer 1

• Proximal fibres of the adductor pollicis muscle make up oblique head and arise from bases of 2nd and 3rd metacarpal and the capitate bone
• The transverses head arises from anterior surface of the body of the 3rd metacarpal

Question 2

What is the insertion of the adductor pollicis muscle?

Answer 2

-Both heads of the adductor pollicis muscle converge on a sesamoid bone on the medial or ulnar side of the metacarpophalangeal joint. -They attach to the base of the proximal phalanx of the thumb.

Question 3

What is the action of the adductor pollicis muscle?

Answer 3

Adducts the proximal phalanx of the thumb toward the middle digit

Question 4

What is the innervation of the adductor pollicis muscle?

Answer 4

• Deep branch of the ulnar nerve (C8 and T1)
• The adductor pollicis muscle is not considered a thenar muscle. Although it acts on the thumb, it is innervated by the ulnar nerve

Question 5

How is the adductor pollcicis muscle tested?

Answer 5

• asking the patient to adduct the thumb against resistance
• This is done by having the patient place the thumb in a fully abducted position (at right angles to the supinated palm, sticking straight up in the air) and then by providing resistance as the patient tries to move the thumb back into an adducted position (flat in the palm just lateral to the index finger).

Question 6

What is the origin of the Abductor digiti minimi muscle?

Answer 6

Abductor digiti minimi muscle arises from the pisiform bone and the tendon of the flexor carpi ulnaris muscle

Question 7

What is the insertion of Abductor digiti minimi muscle?

Answer 7

Attaches to the medial side of the base of the proximal phalanx of the 5th digit

Question 8

What is the action of Abductor digiti minimi muscle?

Answer 8

Abducts the 5th digit

Question 9

What is innervation of the Abductor digiti minimi muscle?

Answer 9

Deep branch of the ulnar nerve (C8 and T1)

Question 10

What are the hypothenar muscle?

Answer 10

• The abductor digiti minimi muscle is 1 of the 3 muscles that make up the hypothenar muscles, which constitute the intrinsic muscles of the little finger.
• All are innervated by deep branches of the ulnar nerve and supplied by deep branches of the ulnar artery.

Question 11

How do you clinically test the Abductor digiti minimi muscle?

Answer 11

• having the patient abduct the little finger against resistance
• With the palm supinated and fingers extended and together, ask the patient to abduct the little finger (move it medially away from the palm and other fingers) while providing resistance.

Question 12

What is the origin of the Flexor digiti minimi brevis muscle?

Answer 12

arises from the hook of the hamate bone and the flexor retinaculum

Question 13

What is the insertion of Flexor digiti minimi brevis muscle?

Answer 13

-Medial aspect of the base of the proximal phalanx of the little finger as does the abductor digiti minimi

Question 14

What is the action of Flexor digiti minimi brevis muscle?

Answer 14

Flexes the proximal phalanx of the 5th digit at the metacarpophalangeal joint

Question 15

What is the innervation of Flexor digiti minimi brevis muscle?

Answer 15

Deep branch of the ulnar nerve (C8 and T1)

Question 16

Is the Flexor digiti minimi brevis muscle part of the hypothenar muscles?

Answer 16

• The flexor digiti minimi brevis muscle is 1 of the 3 muscles that make up the hypothenar muscles, which constitute the intrinsic muscles of the little finger.
• All are innervated by deep branches of the ulnar nerve and supplied by deep branches of the ulnar artery.

Question 17

How do you test the flexor digiti minimi brevis muscle?

Answer 17

• asking the patient to flex the little finger at the metacarpophalangeal joint against resistance
• It helps to hold the middle 3 fingers in an extended position while the patient tries to flex the 5th digit, which should be extended at the interphalangeal joints.

Question 18

Where is the origin of the Opponens digiti minimi muscle?

Answer 18

arises form the hook of hamate bone ad flexor retinaculum

Question 19

Where does the Opponens digiti minimi muscle insert?

Answer 19

inserts on the palmar surface of the body of the 5th metacarpal

Question 20

What is the action of Opponens digiti minimi muscle?

Answer 20

• Abducts
• Flexes
• Laterally rotates 5th metacarpal, enhancing cupping of hand, increasing power of grip and opposing the little finger to the thumb

Question 21

What is the innervation of Opponens digiti minimi muscle?

Answer 21

Deep branch of ulnar nerve (C8 and T1)

Question 22

is the Opponens digiti minimi muscle part of the hypothenar muscles?

Answer 22

• The opponens digiti minimi muscle is 1 of the 3 muscles that make up the hypothenar muscles, which constitute the intrinsic muscles of the little finger.
• All of these muscles are innervated by deep branches of the ulnar nerve and supplied by deep branches of the ulnar artery.

Question 23

How do you test the Opponens digiti minimi muscle?

Answer 23

To clinically test opposition, have the patient touch the tips of the thumb and little finger together and then, with a finger on the patient’s thenar and hypothenar eminence, try to pull the opposed fingers apart to test the strength of the opponens muscles

Question 24

Where do the lumbrical muscles 1 and 2 arise from?

Answer 24

2 lateral tendons of the flexor digitorum profundus

Question 25

Where do the lumbrical muscles 3 and 4 arise from?

Answer 25

3 medial tendons of flexor digitorum profundus

Question 26

What is the insertion of lumbrical muscles?

Answer 26

Attach to the lateral sides of the extensor expansions of digits 2 through 5 (index finger to little finger)

Question 27

What is the action of the lumbrical muscles?

Answer 27

Flex the metacarpophalangeal joints and extend the interphalangeal joints

Question 28

What are lumbricals 1 and 2 innervated by?

Answer 28

median nerve (C8 and T1)

Question 29

What are lumbricals 3 and 4 innervated by?

Answer 29

deep branch of ulnar nerve (C8 and T1)

Question 30

What might the lumbricals prevent?

Answer 30

- Because of the way the lumbricals pass by the proximal interphalangeal joint, they prevent the extensor digitorum from hyperextending the joint. - The lumbrical muscles may exhibit considerable variation in their attachments.

Question 31

How do you test the lumbricals?

Answer 31

The lumbricals can be tested clinically by having the patient flex the 4 medial metacarpophalangeal joints against resistance while keeping the interphalangeal joints extended

Question 32

Where do the 4 dorsal interosseous muscles origin?

Answer 32

- The 4 dorsal interosseous muscles are bipennate. | - They arise by 2 heads from adjacent sides of the metacarpal bones.

Question 33

Where do 4 dorsal interosseous muscles insert?

Answer 33

-Each interosseous muscle inserts into the base of the proximal phalanx and into the aponeurosis that forms the extensor expansion of digits 2 through 4.

Question 34

What is the action of the 4 dorsal interosseous muscles?

Answer 34

- Abducts the fingers from an imaginary longitudinal line through the middle finger (arrows). - Also, the dorsal interossei flex the fingers at the metacarpophalangeal joints and aid in extension of the 2 distal phalanges at the interphalangeal joints.

Question 35

What is the innervation of the 4 dorsal interosseous muscles?

Answer 35

Deep palmar branch of the ulnar nerve (C8 and T1)

Question 36

What is good about the 1st dorsal interosseous muscle?

Answer 36

1. The 1st dorsal interosseous is the largest. It fills the space between the metacarpal bones of the thumb and index finger and is sometimes referred to as the "pinch" muscle. 2. The 1st dorsal interosseous also is used with the adductor pollicis muscle during a precision grip

Question 37

How do you test the 4 dorsal interosseous muscles?

Answer 37

The dorsal interossei are clinically tested by holding the adducted extended fingers together and asking the patient to spread the fingers (abduct them) against this resistance

Question 38

Where do the 3 palmar interossei muscles arise?

Answer 38

-The 3 palmar interossei muscles arise from the palmar surfaces of the metacarpal bones of digits 2, 4, and 5.

Question 39

Where do the 3 palmar interossei muscles insert?

Answer 39

Tendons of the palmar interossei insert into the extensor expansions of the digits and bases of the proximal phalanges of digits 2, 4, and 5

Question 40

What is the action of the 3 palmar interossei muscles?

Answer 40

1. The palmar interossei adduct the fingers at the metacarpophalangeal joint, moving them toward an imaginary line through the axis of the middle finger (arrows). 2/ They also assist in flexing the proximal phalanx at the metacarpophalangeal joint and aid in extension of the 2 distal phalanges at the interphalangeal joints.

Question 41

What is the innervation of the 3 palmar interossei muscles?

Answer 41

- Deep branch of the ulnar nerve (C8 and T1) | - The 3 unipennate palmar interossei are smaller than the 4 dorsal interossei

Question 42

How do you test the plamar interossei?

Answer 42

- asking the patient to hold a sheet of paper between 2 adjacent adducted fingers - As the patient holds the paper, the examiner tries to pull the paper away - With weakened adduction, the patient will have difficulty holding the sheet of paper between the fingers.

Question 43

What do the muscles at the base of the thumb compose?

Answer 43

-Thenar cone or eminence

Question 44

What do the intrinsic muscles at the base of the 5th digit make up?

Answer 44

Intrinsic muscles at the base of the 5th digit make up the hypothenar eminence

Question 45

What abduct and adduct?

Answer 45

1. The palmar interosseous muscles adduct the middle 3 fingers, whereas the dorsal interosseous muscles abduct the middle 3 fingers. 2. Together, the interossei also flex the metacarpophalangeal joint and, because of their insertion into the extensor expansion, extend the proximal and distal interphalangeal joints.

Question 46

Why is the palm susceptible to infection?

Answer 46

- Several potential spaces exist in the palm and can become sites of infection. - The thenar space exists just anterior to the adductor pollicis muscle. - The midpalmar space exists posterior (deep) to the central compartment that contains the long flexor tendons and lumbrical muscles.