FOREARM, WRIST & HAND

Question 1

Arrange the 8 carpal bones from the lateral to proximal sides of the hand.

Answer 1

Scaphoid, Lunate, Triquetrum, Pisiform, Hamate, Capitate, Trapezoid, Trapezium.
“So Long To Pinky, Here Comes The Thumb.”

Question 2

Describe what happens in a Colles’ Fracture.

Answer 2

A fall on an outstretched hand causes the distal radius to deviate/fracture. A FOOSH injury.

Question 3

Describe what happens in a Scaphoid Fracture.

Answer 3

A hard impact not the thenar eminence can lead to swelling of the anatomical snuffbox. This can cause osteonecrosis of the proximal scaphoid, since the distal portion is supplied with blood from a branch of the radial artery.

Question 4

Differentiate the functions and locations of the radioulnar joint from the radiocarpal joint.

Answer 4

Radioulnar joint connects the radius to the ulna proximal to the elbow and protonates/supinator the forearm. The Radiocarpal joint connects the distal head of the radius to the Scaphoid and Lunate carpals. This is responsible for flexing/extending, abducting/adducting and circumducting the hand at the wrist.

Question 5

Describe the functions of the carpometacarpal joint.

Answer 5

This joint is at the articulation of the carpal bones and the metacarpals. It can flex/extend, abduct/adduct, or cause opposition/reposition of the wrist.

Question 6

Describe the nerves that innervate the Flexor Digitorum Profundus and how they do it.

Answer 6

FDP is innervated by the median nerve in all 5 digits for sensory input. It is innervated by the Ulnar nerve for 4th and 5th digits for motor output.

Question 7

What muscles of the “anterior” forearm does the ulnar nerve innervate?

Answer 7

The Flexor capri ulnaris and 1/2 of the Flexor Digitorum Profundus (FDP for motor) are innervated by this nerve

Question 8

Describe what the Allen test is for.

Answer 8

This involves applying pressure to both radial and ulnar arteries on the side of the wrist. Then releasing the ulnar artery first and waiting for color to return to the hand. If so, like most people, you are “Ulnar-artery dominant”

Question 9

Describe Carpal Tunnel Syndrome.

Answer 9

Inflammation, fluid retention or a dislocated carpal bone can cause pain from the Median nerve leading to paresthesia (motor weakness) or thenar atrophy over a long period of time.

Question 10

Define the 18 intrinsic hand muscles.

Answer 10

4 Lumbricals, 3 thenar muscles (abductor, flexor and opponens pollicis brevis), 7 Interossei (3 palmar adductors + 4 dorsal abductors), 3 hypothenar Muscles (abductor, flexor and opponens digiti minimi) AND 1 adductor pollicis brevis

Question 11

For sensory innervation of the hand, the more superior rami cover the more ________ surfaces, while the inferior rami cover the _________ surfaces. For instance, sensory innervation of the thumb is at level ____.

Answer 11

Lateral, Medial;

C6

Question 12

For motor innervation, the more superior ramis are more ______ in the upper limb, whereas the inferior ramis are _______. For instance, _____ levels cover the shoulder area, whereas ______ levels cover the hand.

Answer 12

Proximal, Distal;

C5/C6; C8/T1

Question 13

Regarding arterial supply to the hand, the ulnar artery branches into the ______ palmar arch; while the radial artery branches into the ________ palmar arch. Laceration at the ____ of the hand can be dangerous.

Answer 13

Superficial,
Deep;
Sides

Question 14

Define Lumbrical muscles

Answer 14

Hand muscles that flex at the MP and extend at the IP (proximal and distal).
“Sock-puppet” muscles.

Question 15

Define interosseus muscles.

Answer 15

7 Muscles, in total, that ADDUCT if on the dorsal side, or ABDUCT if on the palmar side of the hand.
“3 Pads for 4 Dabs”

Question 16

What are the 3 rules for forearm muscles and their actions?

Answer 16

1. Muscles are named on Action.
2. Muscles act on the most Distal joint, if it crosses more than one.
3. Deeper goes Distal! Superficial muscles are more proximal.

Question 17

What is the function and location of the Brachioradialis?

Answer 17

This is a posterior forearm flexor that cross the elbow joint. It semi-protonator and flexes the forearm at the elbow.

Question 18

List the muscles in the 3 levels of the anterior forearm.

Answer 18

Superficial: protonator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris;
Intermediate: flexor digitorum Superficialis (FDS);
Deep: Flexor digitorum profundus (FDP), flexor pollicis longus, protonator Quadratus

Question 19

What structures on the forearm do not pass under the flexor retinaculum?

Answer 19

The ulnar artery and ulnar nerve do not pass under the Carpal’s tunnel.

Question 20

Considering the sensory innervation of the hand, the ________ nerve (C__ to C__) handles the radial 3.5 digits; whereas the _________ nerve (C__ to ___) deals with the remaining 1.5 digits.

Answer 20

Median nerve (C5-C7);
Ulnar nerve (C8-T1)

Question 21

Describe what causes Lateral Epicondylitis.

Answer 21

Inflammation of a common extensor near the lateral epicondyle. It is common occurrence with a tennis player’s backhand.

Question 22

The Adductor Pollicis is not a _______ muscle because it is innervated by the _______ nerve.

Answer 22

Not a thenar muscle;

Ulnar nerve