radioulnar joint

anatomy

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 13, 2026

Quick Summary

The radioulnar joint refers to the articulation between the radius and the ulna, the two bones of the forearm. These bones run parallel to each other and are connected by an interosseous membrane.

The radius is the outer bone when the palm faces forward, and its disk-shaped head articulates with the humerus (upper arm bone) and the ulna. The ulna is the inner bone and has a C-shaped notch that forms the elbow joint with the humerus. Both bones have styloid processes at their lower ends, which contribute to the wrist joint. The radioulnar joints allow for pronation (turning the palm downward) and supination (turning the palm upward) of the hand.123

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

3 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

wrist
…several component joints: the distal radioulnar joint, which acts as a pivot for the forearm bones; the radiocarpal joint, between the radius and the first row of carpal bones, involved in wrist flexion and extension; the midcarpal joint, between two of the rows of carpal bones; and various intercarpal joints,…
Read More
…several component joints: the distal radioulnar joint, which acts as a pivot for the forearm bones; the radiocarpal joint, between the radius and the first row of carpal bones, involved in wrist flexion and extension; the midcarpal joint, between two of the rows of carpal bones; and various intercarpal joints,…
Read More