2.4. The Radio-Ulnar Joint

Question 1

What are the Radio-Ulnar Joints?

Answer 1

Locations at which the Radius and the Ulna unite in the Forearm

Question 2

How many Radio-Ulnar Joints are there?

Answer 2

2

Question 3

What are the names of the 2 Radio-Ulnar Joints?

Answer 3

1. Proximal Radio-Ulnar Joint

2. Distal Radio-Ulnar Joint

Question 4

Where is the Proximal Radio-Ulnar Joint located?

Answer 4

Immediately Distal to the Elbow Joint

Question 5

What are the Articulating Surfaces in the Proximal Radio-Ulnar Joint?

Answer 5

1. Radial Head

2. Radial Notch of the Ulna

Question 6

What Type of Joint is the Proximal Radio-Ulnar Joint?

Answer 6

Synovial Pivot

Question 7

What Encloses the Proximal Radio-Ulnar Joint?

Answer 7

The same Joint Capsule as the Elbow Joint

Question 8

What holds the Radial Head in place?

Answer 8

The Radial Annular Ligament

Question 9

How is the Radial Annular Ligament described?

Answer 9

As a “Collar” around the Joint

Question 10

What lines the Radial Annular Ligament?

Answer 10

A Synovial Membrane

Question 11

What is the purpose of the Synovial Membrane which lines the Radial Annular Ligament?

Answer 11

To reduce friction during movement

Question 12

How is movement produced at the Proximal Radio-Ulnar Joint?

Answer 12

The Radial Head rotating inside the Radial Annular Ligament

Question 13

What movements can occur at the Proximal Radio-Ulnar Joint?

Answer 13

1. Pronation

2. Supination

Question 14

Where is the Distal Radio-Ulnar Joint located?

Answer 14

Immediately Proximal to the Wrist Joint

Question 15

What are the Articulating Surfaces in the Distal Radio-Ulnar Joint?

Answer 15

1. Ulnar Notch of the Radius

2. Ulnar Head

Question 16

What Type of Joint is the Distal Radio-Ulnar Joint?

Answer 16

Synovial Pivot

Question 17

What Ligaments strengthen the Distal Radio-Ulnar Joint?

Answer 17

1. Anterior Ligament
2. Posterior Ligament
3. Fibrocartilaginous Ligament

Question 18

What is the Fibrocartilaginous Ligament also known as?

Answer 18

Articular Disk

Question 19

What are the functions of the Articular Disk?

Answer 19

1. Binds the Radius and the Ulna together (holds them together during movement)
2. Separates the Distal Radio-Ulnar Joint from the Wrist Joint

Question 20

What movements can occur at the Distal Radio-Ulnar Joint?

Answer 20

1. Pronation

2. Supination

Question 21

How is movement produced at the Distal Radio-Ulnar Joint?

Answer 21

The Ulna Notch of the Radius slides Anteriorly over the Ulnar Head

Question 22

What are the main Muscles producing Pronation?

Answer 22

1. Pronator Quadratus

2. Pronator Teres

Question 23

What are the main Muscles producing Supination?

Answer 23

1. Supinator

2. Biceps Brachii

Question 24

What Accessory Muscles produce Pronation?

Answer 24

1. Flexor Carpi Radialis
2. Palmaris Longus
3. Brachioradialis

Question 25

What Accessory Muscles produce Supination?

Answer 25

1. Extensor Pollicis Longus

2. Extensor Carpi Radialis Longus

Question 26

What Muscle is the most Powerful Pronator in the Forearm?

Answer 26

Pronator Teres

Question 27

What Muscle is the most Powerful Supinator in the Forearm?

Answer 27

Biceps Brachii (Only in Heavy Loads)