Elbow Joint - Bones, Joints and Muscles

Question 1

What are the two articulate surfaces on the Humerus which is apart of the Elbow joint?

Answer 1

• Trochlea (Medial)

- Capitulum (Lateral)

Question 2

What are the physical features of the forearm articulating with Humerus to make the Elbow joint?

Answer 2

• Trochlear Notch (Where Humerus fits)
• Olecranon Process (Most posterior)
• Coronoid Process (Medial)
• Radial Notch (Lateral)

Question 3

What is the physical articulations of the Radius in elbow joint?

Answer 3

• Capitulum

- Radial head (Slight concavity allows rotation)

Question 4

What are the attachments of the joint capsule of the elbow anteriorly and posteriorly?

Answer 4

Anteriorly: 
- Starts on the margin of the Trochlear Notch 
- Around Coronoid fossa
- Attaches to the Annular Ligament 
- Around the capitulum and radial fossa
Posteriorly: 
- Margins the Trochlear fossa
- Around the Olecarnon fossa

Question 5

What is the purpose of the fossa in the elbow joint?

Answer 5

In the fossas are pads of fats which cushion the area when the body prominences are in full flexion and extension

Question 6

What is the ‘carrying angle’ of the elbow?

Answer 6

The 10-15 degree angle allows the elbow to clear the hips when walking

Question 7

What are the three medial ligaments of the elbow, what are their insertions?

Answer 7

• Anterior band of Ulnar Collateral ligament: O = Medial Epicondyle I = Coronoid Process
• Posterior band of Ulnar Collateral ligament: O -= Medial Epicondyle I = Olecranon Process
• Oblique band of Ulnar Collateral ligament: O = Olecranon I = Coronoid

Question 8

What are the 2 lateral ligaments of the elbow and what are their insertions?

Answer 8

• Annular Ligament: Encircles the Radial head, cubital fossa.
• Radial Collateral Ligament: O = Lateral Epicondyle I = Annular Ligament

Question 9

What is the purpose of the Annular ligament?

Answer 9

The Annular ligament creates the radial notch for the radial head to fit in and stabilise it so rotational movements can occur. Has a small ligament called Quadrate ligament, which is fairly lax

Question 10

What are the bony landmarks of the shaft and distal end of Radius and Ulna?

Answer 10

• Radial Tuberosity
• Styloid process of Ulna and Radius
• Ulnar notch of Radius
• Interosseous border

Question 11

What is unique of the distal radioulnar joint?

Answer 11

Fibrocartilangous disc, triangular in shape, which allows articulation between the forearm and the carpals. The disc also has a fold in-between in the Ulnar notch of Radius which allows fluidity of supination and pronation

Question 12

What happens with the radius and ulna during supination and pronation; Proximally and distally?

Answer 12

• Ulna doesn’t move during these movements
• Proximally, the radius stays in position but rotates 180
• Distally, the radius rotates 180 and moves to lie medially to the ulna

Question 13

What are the three flexors of the elbow?

Answer 13

• Bicep Brachii
• Brachialis
• Brachioradialis

Question 14

What are the insertions and actions of the Bicep Brachii?

Answer 14

• Short head: O = Coracoid Process
• Long head: O = Supraglenoid tubercle
  Insertion: Radial Tubercle
  Actions: Flexion and Supination

Question 15

What are the insertions and actions of Brachilais and Brachioradialis?

Answer 15

Brachialis: 
O = Distal half of anterior aspect of humerus 
I = Coronoid Process of Ulna
Action = Flexion (Slow Twitch muscle)
Brachioradialis: 
O = Lateral Epicondyle of Humerus 
I = Proximal to Radial Styloid Process 
Actions = Flexion (While in mid pronation)

Question 16

What are the insertions and actions of Triceps Brachii?

Answer 16

Medial Head: Posterior surface of humerus, inferior of spiral groove
Lateral Head: Posterior surface of humerus, superior of spiral groove
Long Head: Infraglenoid tubercle of scapula
Insertion: Via an aperoneurosis to a tendon which inserts to the Olecranon fossa
Action: Extension