Elbow Forearm and Wrist

Question 1

The forearm contains two bones:

Answer 1

Radius and Ulna

Question 2

Connects radius and ulna

Answer 2

Interosseous membrane

Question 3

What type of joint is the elbow?

Answer 3

Hinge type synovial joint

Question 4

The elbow is composed by 3 separate joints:

Answer 4

Humero-ulnar joint
Humeroradial joint
Proximal Radio-ulnar joint

Question 5

Humero-ulnar joint

Answer 5

Between the trochlea of the humerus and the trochlear notch of the ulna
Also, the coronoid process of the ulna is in contact with the coronoid fossa of the humerus during flexion of the elbow.

Question 6

Humeroradial Joint

Answer 6

Between the capitulum of the humerus and the head of the radius is in contact with the radial fossa of the humerus
Function:
Flexion and extension of the forearm
Supination and pronation

Question 7

Proximal Radio-ulnar joint

Answer 7

Between the radial notch of the ulna and the head of the radius
Pivot joint
The head of the radius is attached to the ulna through the anular ligament
Function:
Pronation and Supination

Question 8

Ligaments of the elbow joint

Answer 8

Radial collateral ligament
Anular ligament
Ulnar collateral ligament

Question 9

Anular ligament of radius

Answer 9

Provides support to the radial ulnar joint

Question 10

Radial collateral ligament

Answer 10

Provides support to the Humeroradial joint

Question 11

Ulnar collateral ligament

Answer 11

Contains an anterior band, posterior band, and oblique band
Provides support humeroulnar joint

Question 12

Distal Radio-Ulnar Joint

Answer 12

The head of the ulna is accommodated by the ulnar notch of the radius
Fibrocartilaginous, triangular articular disc of the distal radio-ulnar joint (triangular ligament) binds the ends of the ulna and radius together and is the main uniting structure of the joint

Question 13

Supinator

Answer 13

Forearm muscle, brings support to elbow joint.
Innervated by ulnar nerve
Function: Supination of forearm

Question 14

Pronator Teres

Answer 14

Primary pronator muscle of the forearm (proximal to elbow joint)
Innervated by median nerve (C6,C7)
Function
Pronation of forearm

Question 15

Pronator quadratus

Answer 15

Secondary pronator muscle of the forearm (proximal to elbow joint)
Innervated by ulnar nerve
Function
Pronation of forearm

Question 16

Clinical correlations
subcutaneous olecranon bursitis

Answer 16

AKA “miners elbow” “students elbow”
Subcutaneous olecranon bursa is exposed to injury during falls on the elbow

Repeated excessive pressure and friction may cause this bursa to become inflamed

Question 17

Clinical correlations
subtendinous olecranon bursitis

Answer 17

Less common
Results from excessive friction between the triceps tendon and olecranon, for example, resulting from repeated flexion-extension of the forearm.

Pain is most severe during flexion of the forearm because of pressure exerted on the inflamed subtendinous olecranon bursa by triceps tendon

Question 18

Clinical correlations
Avulsion of medial epicondyle

Answer 18

In children can result from a fall that causes severe abduction of the extended elbow. An abnormal movement of this articulation. The resulting traction on the ulnar collateral ligament pulls the medial epicondyle before entering the forearm.

The anatomical basis of this avulsion is that the medial epicondyle may not fuse with the distal end of the humerus until age 20

Question 19

Clinical correlations
Subluxation and dislocation of radial head

Answer 19

The child is suddenly lifted by the upper limb while the forearm is pronated. Sudden pulling of the upper limb tears the distal attachment of the angular ligament, which it is loosely attached to the neck of the radius.

Radial head then moves distally, partially out of the socket formed by the anular ligament

Question 20

Tennis elbow (lateral epicondylitis)

Answer 20

Painful musculoskeletal condition that may follow repetitive use of superficial extensor muscles of the forearm.
Pain is felt over the lateral epicondyle and radiates down the posterior surface of the forearm.

Question 21

Muscles of the forearm
Anterior compartment (Flexor and pronator compartment)
Superficial layer

Answer 21

Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris

Question 22

Pronator Teres

Answer 22

Has two heads
Ulnar head and Radial head
Innervation: Median nerve (C6,C7)
Function: Pronates and flexes forearm

Question 23

Flexor Carpi radialis

Answer 23

Innervated by Median nerve (C6,C7)
Flexes and abducts hand

Question 24

Palmaris longus

Answer 24

Innervated by: Median Nerve (C7,C8)
Flexes hand and tenses palmar aponeurosis

Question 25

Flexor carpi ulnaris

Answer 25

Has two heads Ulnar head and Radial head Innervation: Ulnar nerve (C7,C8) Flexes and adducts the hand

Question 26

Muscles of the forearm Anterior compartment (Flexor and pronator compartment) Intermediate layer

Answer 26

Flexor Digitorum Superficialis

Question 27

Flexor Digitorum Superficialis

Answer 27

Has two heads Humero-ulnar head and Radial head Innervation: Median nerve (C7,C8,T1) Function: Flexes middle phalanges at proximal interphalangeal joints of middle four digits: acting more strongly, it also flexes proximal phalanges at metacarpophalangeal joints.

Question 28

Muscles of the forearm Anterior compartment (Flexor and pronator compartment) Deep layer

Answer 28

Flexor Digitorum profundus Flexor Pollicis longus Pronator Quadratus

Question 29

Flexor Digitorum profundus

Answer 29

Contains Medial and Lateral Part Medial Part is innervated by Ulnar Nerve (C8,T1) Main action: Flexes distal phalanges 4 and 5 at distal interphalangeal joints Lateral Part is innervated by the anterior interosseous nerve, from median nerve (C8,T1) Main action: Flexes distal phalanges 2 and 3 at distal interphalangeal joints

Question 30

Flexor Pollicis longus

Answer 30

Innervated by anterior interosseous nerve, from median nerve (C8,T1) Main action: Flexes phalanges of 1st digit

Question 31

Pronator Quadratus

Answer 31

Innervated by anterior interosseous nerve, from median nerve (C8,T1) Pronates forearm, deep fibers bind radius and ulna together

Question 32

Muscles of the forearm Posterior compartment (Extensor and supinator compartment) Superficial layer

Answer 32

Brachioradialis Muscles that originate from the lateral epicondyle Extensor carpi radialis brevis Extensor carpi radialis longus Extensor digitorium Extensor digiti minimi Extensor carpi ulnaris

Question 33

Brachioradialis

Answer 33

Innervation Radial nerve (C5,C6,C7) Function: Relatively weak flexion of forearm; maximal when forearm is in mid-pronated position

Question 34

Extensor carpi radialis brevis

Answer 34

Innervation: Radial Nerve (C6, C7) Function: Extend and abduct hand at the wrist joint ; ECRL active during fist clenching

Question 35

Extensor carpi radialis longus

Answer 35

Innervation Deep Branch of radial nerve (C7,C8) Function: Extend and abduct hand at the wrist joint ; ECRL active during fist clenching

Question 36

Extensor digitorum

Answer 36

Innervation: Deep Branch of radial nerve (C7,C8) Function: Extends medial four digits primarily at metacarpophalangeal joints, secondarily at interphalangeal joints

Question 37

Extensor digiti minimi

Answer 37

Innervation: Deep Branch of radial nerve (C7,C8) Function: Extends 5th digit primarily at metacarpophalangeal joints, secondarily at interphalangeal joints

Question 38

Extensor carpi ulnaris

Answer 38

Innervation: Deep Branch of radial nerve (C7, C8) Function:Extend and adduct hand at the wrist joint ; ECRL active during fist clenching

Question 39

Muscles of the forearm Posterior compartment (Extensor and supinator compartment) Deep layer

Answer 39

Supinator Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Extensor indicis

Question 40

Supinator

Answer 40

Innervation: Deep branch of radial nerve (C7,C8) Function: Supinates forearm: rotates radius to turn palm anteriorly or superiorly (if elbow is flexed)

Question 41

Abductor pollicis longus

Answer 41

Innervation: Posterior interosseous nerve (C7, C8), a continuation of deep branch of radial nerve Function: Abducts thumb and extends it at the carpometacarpal joint

Question 42

Extensor pollicis brevis

Answer 42

Innervation: Posterior interosseous nerve (C7,C8), a continuation of deep branch of radial nerve Function: Extends proximal phalanx of thumb at metacarpophalangeal joint; extends carpometacarpal joint

Question 43

Extensor pollicis longus

Answer 43

Innervation: Posterior interosseous nerve (C7,C8), continuation of deep branch of radial nerve Function: Extends distal phalanx of thumb at metacarpophalangeal joint; extends carpometacarpal joint

Question 44

Extensor indicis

Answer 44

Innervation: Posterior interosseous nerve (C7,C8), continuation of deep branch of radial nerve Function: Extends 2nd digit (enabling its independent extension) helps extend hand at wrist