The forearm contains two major bones. One is the ulna, and the other is the radius. In concert with each other, the two bones play a vital role in how the forearm rotates. The ulna primarily connects with the humerus at the elbow joint, while the radius primarily interacts with carpals of the hand at the wrist joint. The two bones play only secondary roles at their opposing joints. The radius is the home for a few muscles' insertion points. The biceps originate near the shoulder joint and inserts into the radial tuberosity on the upper part of the radius, near the elbow joint. Other muscle attachments include the supinator, the flexor digitorum superficialis, the flexor pollicis longus, the pronator quadratus, and many more tendons and ligaments. Given the human impulse to break a fall by outstretching the arms, the radius is one of the more frequently fractured bones in the body. Also, dislocation issues with both the wrist and the elbow may arise.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Radius