Upper limb 1.3

Question 1

What is the origin of the flexor pollicis longus muscle?

Answer 1

From anterior aspect of radius and adjacent interosseous membrane

Question 2

What is the insertion of the flexor pollicis longus muscle?

Answer 2

Inserts on base of distal phalanx of the thumb

Question 3

What is the action of the flexor pollicis longus muscle?

Answer 3

• Flexion of distal phalanx of thumb

- Can also flex the proximal phalanx because its tendon crosses that joint

Question 4

What is the innervation of the flexor pollicis longus muscle?

Answer 4

Median nerve (anterior interosseous brunch). C8, C7, T1

Question 5

What is the tendon of the unipennate belly of the flexor of pollicis longus muscle like?

Answer 5

• The tendon of the unipennate belly of the flexor pollicis longus muscle crosses the carpal canal on the lateral or radial side of the digital flexor tendons and passes to the distal phalanx of the thumb.
• The tendon has its own synovial sheath.

Question 6

How do you test the flexor pollicis longus muscle?

Answer 6

• asking the patient to flex the tip of the thumb against resistance while the examiner holds the proximal phalanx fixed between the thumb and fingers
• This action not only tests the strength of muscle contraction but also tests the integrity of the median nerve, which innervates this muscle.

Question 7

What is the origin of the supinator muscle?

Answer 7

Arises from lateral epicondyle of humerus, the radial collateral ligament of the elbow joint, the angular ligament of the proximal radioulnar joint, the supinator fossa and crest of the ulna

Question 8

What is the insertion of the supinator muscle?

Answer 8

Inserts into lateral, posterior and anterior surfaces of the proximal third of the radius

Question 9

What is the action of the supinator muscle?

Answer 9

• ROTATES THE RADIUS TO SUPINATE THE FOREARM AND HADN

- Supination occurs whether the forearm is flexed or extended

Question 10

What is the innervation of the supinator muscle?

Answer 10

Deep branch of the radial nerve (C5 and C6)

Question 11

What is the blood supply for the supinator muscle?

Answer 11

posterior interosseous artery

Question 12

What are the different supinators?

Answer 12

• Most powerful supinator of forearm is biceps brachii which acts when forearm flexed
• Supinator can supinate a forearm that is flexed or extended

Question 13

What is posterior compartment neuropathy?

Answer 13

1. The deep branch of the radial nerve (the radial nerve’s motor component) can become compressed as it passes through the supinator, leading to a posterior compartment neuropathy, resulting in weakened extension of the wrist and fingers.
2. The supinator is tested clinically by having the patient supinate the extended forearm against resistance

Question 14

Where does the brachioradilias muscle arise from?

Answer 14

Proximal two thirds of lateral supracondylar ridge of the distal humerus and intermsucular septum

Question 15

Where does the brachioradialis muscle insert?

Answer 15

On lateral aspect of the distal radius just proximal to the styloid process

Question 16

What is the action of the brachioradialis muscle?

Answer 16

An accessory flexor of the forearm at the elbow

Question 17

What is the innervation of the brachioradilias?

Answer 17

Radial nerve C5 and C6 before it divides into its superficial and deep beaches

Question 18

Why is the brachioradilis unique?

Answer 18

• Muscle of posterior compartment by a weak flexor of forearm at elbow and is most efficient as flexor when the forearm is in midpronation
• Innervated by radial nerve not an extensor or supinator

Question 19

What is tennis elbow?

Answer 19

1. If one tests forearm flexion against resistance in the midpronated position, the brachioradialis is easily seen as a muscle bulge over the lateral epicondyle of the elbow. 2. Pain over the lateral epicondyle is often referred to as “tennis elbow,” but this muscle pain, usually from overexertion, can be caused by a number of actions, including playing tennis or golf or lifting heavy objects (e.g., a suitcase) by a handle.

Question 20

Where does the extensor carpi radialis longus muscle arise from?

Answer 20

lateral supracondylar ridge of humerus

Question 21

Where does the extensor carpi radialis longus muscle attach to?

Answer 21

attaches to base of 2nd metacarpal

Question 22

What is the action of the extensor carpi radialis longus?

Answer 22

Extends and abducts the hand at the wrist joint

Question 23

What is the innervation of the extensor carpi radialis longus?

Answer 23

Radial nerve (C6 and C7)

Question 24

what is needed for a power grip?

Answer 24

• The extensor carpi radialis longus muscle arises just distal to the brachioradialis muscle. -Its belly ends in the proximal third of the forearm.
• Its flat tendon continues distally along the lateral border of the radius beneath the abductor pollicis longus and extensor pollicis brevis muscles.
• This muscle also acts synergistically during flexion of the fingers by extending the hand at the wrist to give additional strength when the hand grasps an object. This action is essential for a power grip.

Question 25

How do you test the extensor carpi radialis longus muscle?

Answer 25

- the patient extend and abduct the hand at the wrist against resistance - this requires that the examiner hold the patient’s fist and apply resistance to the lateral aspect of the wrist while the patient tries to bend the fist laterally (abduct or move it toward the thumb side of the wrist) and extend the wrist simultaneously.

Question 26

Where does the Extensor carpi radialis brevis muscle arise from?

Answer 26

From lateral epicondyle of the humerus

Question 27

Where does the Extensor carpi radialis brevis muscle insert?

Answer 27

On the base of the 3rd metacarpal bone

Question 28

What is the action of the Extensor carpi radialis brevis muscle?

Answer 28

Extend and abducts the hand at the wrist joint

Question 29

What is the innervation of Extensor carpi radialis brevis muscle?

Answer 29

Radial nerve (deep branch) (C7 and C8)

Question 30

What is the difference between Extensor carpi radialis brevis muscle and longus?

Answer 30

- Shorter and thicker that longus which partially covers it - Sometimes both muscles form one bellow that gives rise to two tendons, important for power grip which requires wrist extension

Question 31

How do you test Extensor carpi radialis brevis muscle?

Answer 31

-The extensor carpi radialis brevis muscle acts with the extensor carpi radialis longus and is tested clinically along with that muscle. -The patient is asked to extend and abduct the hand at the wrist against resistance. This action not only tests these 2 muscles but also tests the integrity of the radial nerve (its deep branch).

Question 32

where does the extensor digitorum muscle arise from?

Answer 32

-Lateral epicondyle of the humerus

Question 33

Where does the extensor digitorum muscle insert?

Answer 33

-Insert as extensor expansions of the medial 4 digits (index finger to little finger)

Question 34

What is the action of the extensors digitorum muscle?

Answer 34

Performs extension the metacarpophalangeal and interphanalgeal joints and also participates in wrist extension when fingers are extended

Question 35

What is the innervation of the extensor digitorum muscle?

Answer 35

Radial nerve (posterior interosseous branch) (C7 and C8)

Question 36

What are the tendons of the extensor digitorum muscle?

Answer 36

- The tendons of the extensor digitorum pass through the extensor retinaculum and to the extensor expansions of the medial 4 digits. - Occasionally, this muscle has only 3 tendons instead of 4. - Often, the extensor digiti minimi is attached to the extensor digitorum.

Question 37

How is the extensor digirotum muscle tested clinically?

Answer 37

- having the patient extend the fingers against resistance. - This is best done as one supports the patient’s pronated hand with one hand and provides resistance to the fingers across the metacarpophalangeal joints with the other hand. - The contracting muscle belly will bulge out along the lateral forearm (little finger side in the pronated position).

Question 38

Where does the extensor digiti minimi muscle arise from?

Answer 38

arises from lateral epicondyle of the humerus

Question 39

What does the extensor digiti minimi muscle insert to?

Answer 39

inserts as an extensor expansion of the 5th digit

Question 40

What is the action of the Extensor digiti minimi muscle?

Answer 40

- extends the 5th digit at the metacapophalangeal and interpahalnegal joints - also participates in wrist extension when fingers are extended

Question 41

What is the innervation of the Extensor digiti minimi muscle?

Answer 41

- The slender extensor digiti minimi muscle is often connected to the larger extensor digitorum - Radial nerve (posterior interosseous branch) (C7 and C8)

Question 42

Why is the Extensor digiti minimi muscle hardly tested?

Answer 42

The small extensor digiti minimi muscle acts with many of the other finger and wrist extensors and usually will not be tested clinically as an individual muscle, because its isolated action is difficult to ascertain

Question 43

What is the origin of Extensor carpi ulnaris muscle?

Answer 43

- 2 heads 1. arises from lateral epicondyle of the humerus 2. arises from posterior border of the ulna

Question 44

Where does the Extensor carpi ulnaris muscle attach?

Answer 44

Attaches to medial side of the base of the 5th metacarpal

Question 45

What is the innervation of the Extensor carpi ulnaris muscle?

Answer 45

Radial nerve (posterior interosseous brach) (C7 and C8)

Question 46

What is the action of Extensor carpi ulnaris muscle?

Answer 46

Extends and adducts the hand at the wrist joint

Question 47

How is the extensor carpi ulnaris used in the power grip?

Answer 47

- Similar to the extensor carpi radialis longus and brevis muscles, the extensor carpi ulnaris acts as a synergist to the finger flexors because it keeps the wrist extended to give additional strength when the hand grasps an object. - This action is essential for a power grip.

Question 48

How is the extensor carpi ulnaris tested?

Answer 48

1. the patient extend and adduct the wrist against resistance. 2. The examiner can hold the patient’s pronated fist and provide resistance against wrist extension and adduction (movement toward the little finger side of the wrist). 3. The bulging contracted muscle belly will be evident along the medial forearm and its tendon at the wrist.