The elbow joint is formed by the meeting of three bones: the humerus, radius, and ulna. These bones work together to allow for bending, straightening, and rotating the arm.
The Bones of the Elbow
These three bones articulate to create two key joints in the elbow:
-
Humeroradial joint:
- This joint is where the humerus (upper arm bone) meets the radius (one of the two bones in the forearm).
- It allows for the bending and straightening movements of the arm.
- Think of this as the primary hinge of your elbow.
-
Proximal radioulnar joint:
- This is the meeting point of the radius and the ulna (the other bone in the forearm) near the elbow.
- It facilitates the rotation of the lower arm, allowing you to turn your palm up or down.
- This joint makes it possible for you to twist your forearm.
Key Components Summary
| Bone | Function | Joint Involved |
|---|---|---|
| Humerus | Upper arm bone, articulates with radius and ulna | Humeroradial joint |
| Radius | Forearm bone, articulates with humerus and ulna | Humeroradial, Proximal radioulnar joint |
| Ulna | Forearm bone, articulates with radius | Proximal radioulnar joint |
Therefore, while the term 'elbow bone' is commonly used, it actually refers to the interaction of the humerus, radius, and ulna at two distinct joints - the humeroradial and proximal radioulnar joints, all facilitating the complex motion of the elbow and arm.
