PNS 3 - Median Nerve

Question 1

Muscles Innervated

Answer 1

Flexor Carpi radialis, palmaris longus, pronator quadratus, pronator teres, digital flexors

Question 2

Motor Functions

Answer 2

Thumb extension and opposition, flexion of digits 2 & 3, wrist flexion and abduction, forearm pronation

Question 3

Sensory

Answer 3

Skin over anterolateral surface of hand

Question 4

Common injury sites for Median Nerve at the shoulder

Answer 4

• Dislocation, usually anterior
• Direct trauma, some fractures

Question 5

Common injury sites for Median Nerve at the arm

Answer 5

Fracture of the lower 1⁄4 of the humerus

Question 6

Common injury sites for Median Nerve at the elbow

Answer 6

• Dislocation with anterior displacement, medial epicondylar fracture
• Closed reduction of elbow dislocation leading to intra-articular entrapment.

Question 7

Common injury sites for Median Nerve at the forearm

Answer 7

• Fractures
• Anterior aspect blows, lacerations
• Entrapment beneath FDS

Question 8

Median nerve can be entrapped in the space between the superficial and deep heads of the pronator teres muscle. This relates to what syndrome?

Answer 8

Pronator teres syndrome

Question 9

Causes of Pronator teres syndrome

Answer 9

Elbow trauma, repetitive elbow flexion, supination and pronation of forearm

Question 10

Signs/symptoms of Pronator Teres syndrome?

Answer 10

Chronic forearm pain/aching especially with pronation of forearm and paraesthesias in the median nerve cutaneous supply.

Question 11

Wrist (most common site of median nerve injuries)

Answer 11

• Suicide attempts
• Fractures, dislocations, some sprains

Question 12

Compression of the median nerve as it passes through carpal tunnel beneath the transverse carpal ligament. AKA what syndrome?

Answer 12

Carpal tunnel Syndrome

Question 13

The carpal tunnel is a fibro-osseous tunnel formed by: Laterally?

Answer 13

tubercles of the scaphoid and trapezium

Question 14

The carpal tunnel is a fibro-osseous tunnel formed by: medially?

Answer 14

pisiform and hook of the hamate

Question 15

The carpal tunnel is a fibro-osseous tunnel formed by: Dorsally?

Answer 15

carpal bones

Question 16

The carpal tunnel is a fibro-osseous tunnel formed by: Volarly

Answer 16

flexor retinaculum (transverse carpal ligament)

Question 17

Motor: ORDER OF INNERVATION by Median Nerve

Answer 17

• Pronator Teres
• Palmaris Longus
• Flexor Carpi Radialis
• Flexor Digitorum Profundus (radial 1/2)
• Flexor Pollicis Longus
• Pronator Quadratus
• Abductor Pollicis Brevis
• Opponens Pollicis
• Flexor Pollicis Brevis (superficial 1/2)
• Lumbricals 1 and 2 (MCP flexion at digits 2 and 3)

Question 18

Forearm pronation
SOLE: 2 muscles innervated?

Answer 18

Pronator Teres and Pronator Quadratus

Question 19

Wrist flexion with median nerve is shared with what other nerve?

Answer 19

Ulnar Nerve

Question 20

Wrist flexion with median nerve is shared with what other nerve? What 4 mm do they innervate?

Answer 20

Flexor Carpi Radialis, Flexor Pollicis Longus, Flexor Digitorum
Superficialis (Sublimis), Flexor Digitorum Profundus (Lateral 1⁄2)

Question 21

Wrist Abduction with the median nerve is also share with what other nerve?

Answer 21

RADIAL Nerve

Question 22

Wrist Abduction with the median nerve also shared with RADIAL, what muscle do they innervate?

Answer 22

Flexor Carpi Radialis

Question 23

Median nerve and Thumb Opposition, what muscle?

Answer 23

Opponens Pollicis

Question 24

Median nerve Finger Flexion SOLE: Fingers 2 and 3

Answer 24

lateral 1⁄2 Flexor Digitorum Profundus, Flexor Digitorum Superficialis, Lumbricals 1 and 2

Question 25

Median nerve Finger Flexion shared with this nerve for fingers 4-5?

Answer 25

Ulnar nerve

Question 26

Median nerve Finger Flexion shared with Ulnar for fingers 4-5. What muscle?

Answer 26

Flexor Digitorum Superficialis

Question 27

SENSORY
Area of isolated supply (SOLE):

Answer 27

anterior and posterior aspect of distal tips of
fingers 2 and 3

Question 28

Primary Zone for Median Nerve: Anterior:

Answer 28

Lateral 2/3 of hand (boundaries include midline of 4th digit, wrist line – excluding distal tips of digits 2 and 3)

Question 29

Posterior:

Answer 29

Distal 2/3 fingers 2 and 3, lateral 1⁄2 finger 4 excluding tips of digits 2 and 3.

Question 30

AUTONOMICS T/F
Median Nerve carries majority of autonomic fibres for entire arm, forearm and hand.

Answer 30

True

Question 31

Median Nerve PROPRIOCEPTION is responsible for all of this digits movements?

Answer 31

Thumb

Question 32

Median Nerve PROPRIOCEPTION is responsible for flexor surfaces of fingers ____ and ____ and lateral aspect of _______ joint?

Answer 32

2 and 3
Wrist joint

Question 33

The median nerve is referred to as the
“________ ________” nerve.

Answer 33

tool utilization

Question 34

Median nerve testing

Answer 34

• Rule out C-spine and TOS
• Neural tension test
• Muscle tests: pronator teres, Flexor Digitorum Superficialis (Flexion at DIPs), Thumb opposition. flexion and Abductor pollicis brevis (thumb abduction at the proximal phalanx)
• Special tests: Phalen’s Test and Reverse Phalen’s test, Tinel’s sign at the wrist, Pinch test (O.K sign)