The elbow joint primarily moves through flexion and extension. These movements allow you to bend and straighten your arm.
Elbow Joint Movements
The elbow joint, a hinge joint, facilitates movement primarily in one plane.
- Flexion: This is the movement that decreases the angle of the joint, bringing your forearm towards your upper arm. An example is bending your arm to bring your hand towards your shoulder.
- Extension: This is the movement that increases the angle of the joint, straightening your arm. An example is fully extending your arm straight out in front of you.
While the elbow joint itself is only responsible for flexion and extension, the movement of the forearm is further enhanced by the proximal radioulnar joint. This joint, located near the elbow, works with the elbow joint to create a more extensive range of motion.
Proximal Radioulnar Joint Movements
The proximal radioulnar joint is crucial to the overall movement of the elbow complex. These movements involve the rotation of the forearm:
- Pronation: This is the movement that turns your hand so your palm faces down or backward. For example, rotating your hand to place it palm-down on a table.
- Supination: This is the movement that turns your hand so your palm faces up or forward. For example, turning your palm upwards as if you were holding a bowl of soup.
Summary of Elbow Joint Movement
The following table summarizes the movements at the elbow and proximal radioulnar joints.
| Joint | Movement | Description | Example |
|---|---|---|---|
| Elbow Joint | Flexion | Decreasing the angle of the joint | Bending the arm to touch your shoulder |
| Elbow Joint | Extension | Increasing the angle of the joint | Straightening the arm |
| Proximal Radioulnar Joint | Pronation | Rotating the forearm so the palm faces down or backward | Rotating the forearm to turn a doorknob clockwise |
| Proximal Radioulnar Joint | Supination | Rotating the forearm so the palm faces up or forward | Rotating the forearm to turn a doorknob counter-clockwise |
In conclusion, the elbow joint itself moves only through flexion and extension, but the coordinated action of the proximal radioulnar joint adds pronation and supination movements, allowing for a wide range of motion in the arm.
