2.4. The Radio-Ulnar Joint Flashcards
What are the Radio-Ulnar Joints?
Locations at which the Radius and the Ulna unite in the Forearm
How many Radio-Ulnar Joints are there?
2
What are the names of the 2 Radio-Ulnar Joints?
- Proximal Radio-Ulnar Joint
2. Distal Radio-Ulnar Joint
Where is the Proximal Radio-Ulnar Joint located?
Immediately Distal to the Elbow Joint
What are the Articulating Surfaces in the Proximal Radio-Ulnar Joint?
- Radial Head
2. Radial Notch of the Ulna
What Type of Joint is the Proximal Radio-Ulnar Joint?
Synovial Pivot
What Encloses the Proximal Radio-Ulnar Joint?
The same Joint Capsule as the Elbow Joint
What holds the Radial Head in place?
The Radial Annular Ligament
How is the Radial Annular Ligament described?
As a “Collar” around the Joint
What lines the Radial Annular Ligament?
A Synovial Membrane
What is the purpose of the Synovial Membrane which lines the Radial Annular Ligament?
To reduce friction during movement
How is movement produced at the Proximal Radio-Ulnar Joint?
The Radial Head rotating inside the Radial Annular Ligament
What movements can occur at the Proximal Radio-Ulnar Joint?
- Pronation
2. Supination
Where is the Distal Radio-Ulnar Joint located?
Immediately Proximal to the Wrist Joint
What are the Articulating Surfaces in the Distal Radio-Ulnar Joint?
- Ulnar Notch of the Radius
2. Ulnar Head
What Type of Joint is the Distal Radio-Ulnar Joint?
Synovial Pivot
What Ligaments strengthen the Distal Radio-Ulnar Joint?
- Anterior Ligament
- Posterior Ligament
- Fibrocartilaginous Ligament
What is the Fibrocartilaginous Ligament also known as?
Articular Disk
What are the functions of the Articular Disk?
- Binds the Radius and the Ulna together (holds them together during movement)
- Separates the Distal Radio-Ulnar Joint from the Wrist Joint
What movements can occur at the Distal Radio-Ulnar Joint?
- Pronation
2. Supination
How is movement produced at the Distal Radio-Ulnar Joint?
The Ulna Notch of the Radius slides Anteriorly over the Ulnar Head
What are the main Muscles producing Pronation?
- Pronator Quadratus
2. Pronator Teres
What are the main Muscles producing Supination?
- Supinator
2. Biceps Brachii
What Accessory Muscles produce Pronation?
- Flexor Carpi Radialis
- Palmaris Longus
- Brachioradialis
What Accessory Muscles produce Supination?
- Extensor Pollicis Longus
2. Extensor Carpi Radialis Longus
What Muscle is the most Powerful Pronator in the Forearm?
Pronator Teres
What Muscle is the most Powerful Supinator in the Forearm?
Biceps Brachii (Only in Heavy Loads)
