The elbow

Question 1

*

Describe the purpose and general facts about the elbow

Answer 1

• good stability but less mobility
• used cooperatily for versatility and precision movements of the hand (dexterity)
• complex joint- it is not a simple hinge joint bc it can pronate/supinate too

Question 2

What are the bones of the humerus

Answer 2

• radial fossa
• coronoid fossa
• olecranon fossa
• trochlea
• capitulum (only seen in anterior view)
• med. epicondyle
• lat epicondyle

Question 3

What are the bones in the forearm?

Answer 3

Ulna:
* coronoid process
* olecranon process
* styloid process
* trochlea notch

Radius:
* head
* styloid process
* radial tuberosity

Question 4

What is the humeroulna joint and what does it do?

Answer 4

• true hinge joint
• between trochlea and trochlear notch
• does flexion/extension (1DF)

Question 5

What is the humeroradial joint and proximal radioulnar joint, and what do they do?

Answer 5

Humeroradial:
* gliding joint/restricted ball and socket
* between capitulum of humerus and head of radius

Proximal Radioulnar
* Pivot joint
* between radius and ulna
* allows for radius to crossover ulna and back to parallel again

Question 6

What are the ligaments of the elbow?

Answer 6

• Lateral collateral ligament (outside)
• radial collateral ligament (outside)
• Annular ligament (front)
• Medial collateral ligament (ant., post, and transverese bands)

Question 7

What are the ROM of the elbow?

Answer 7

• Flexion (135-150)
• Extension 0
• Pronation (80-90)
• Supination (80-90)

Question 8

What is the carrying angle?

Answer 8

In an anatomical position, the forearm i abducted in relation to the humerus
* cubitus valgus
* caused by the humerus and ulna articulation
* nornally larger in women (10-15 degrees)
*

Question 9

What are the mucles of the elbow and upper arm?

Answer 9

• brachialis
• Brachioradialis
• pronator teres
• supinator
• Tricpes brachii (long, lateral, medial)
• Biceps brachii (long and short head)

Question 10

OIA for brachialis, brachioradialis, and biceps brachii?

Answer 10

Brachialis: deep to biceps
* O: midshaft humerus
* I: ulnar tuberosity
* elbow flexion

Brachioradialis:
* O: supracondylar notch
* I: radial styloid
* A: elbow flexion ALSO pronation and supination

Biceps Brachii:
* Short Head: O: coracoid process, I: radial tuberosity, A: flex shoulder and elbow, also does supination of elbow
* Long Head: O: supraglenoid tubercle, I: radial tuberosity, A: flex shoulder and elbow, and elbow supination

Question 11

OIA for pronator teres, supinator, and triceps brachii?

Answer 11

Pronator Teres:
* O: medial epicondyle
* I: midshaft of radius
* A: pronation

Supinator:
* O: lateral epicondyle
* I: midshaft of radius
* A: supination

Tricpes Brachii: all insert into olecranon process
Long head:
* O: scapular neck
* A: shoulder and elbow extension
Lateral head:
* O: humerus
* A: elbow extension
Short head:
* O: humerus
* A: elbow extension

Question 12

What is the difference between brachialis, brachioradialis, and biceps brachii?

Answer 12

• The biceps brachii and brachioradialis both insert on the radius, BUT brachialis inserts on the ulna
• This is importnat becuase only the radius moves during pronation and the ULNA does NOT
• So the brachialis is considered the work-horse of the flexors because it works no matter what hand position it is in.

The biceps brachi works in supinated position, brachioradialis in the neutral position, and brachialis best in the pronated position

They all are elbow flexors!

Question 13

Does hand position matter for elbow extension?

Answer 13

No it does not because elbow extension inserts into the olecranon not further down to hand/forearm

• Shoulder position matters though
• Overhead tricp extension works the long head (bc at the shoulder)
• Tricep pull downs work the medial and lateral head