Radius

The radius or radial bone is one of the two large bones of the forearm, the other being the ulna.

It extends from the lateral side of the elbow to the thumb side of the wrist and runs parallel to the ulna.

The ulna is usually slightly longer than the radius, but the radius is thicker.

Therefore the radius is considered to be the larger of the two.

It is a long bone, prism-shaped and slightly curved longitudinally.

The radius is part of two joints: the elbow and the wrist.

At the elbow, it joins with the capitulum of the humerus, and in a separate region, with the ulna at the radial notch. At the wrist, the radius forms a joint with the ulna bone.

The corresponding bone in the lower leg is the fibula.