The role of the ulnar radius is primarily to form the elbow and wrist joints, to provide rotational movements of the forearm, and to play an important role in maintaining the function of the forearm. The ulnar radius is the bone that forms the forearm, and proximally it forms the elbow joint with the distal humerus, and distally it participates in forming the wrist joint. The main rotational function of the forearm is realized by the movement of the radius around the ulna, which is one of the most important functions of the arm. Therefore, an injury to the ulnar radius may lead to dysfunction of the elbow and wrist joints, and may cause impairment (or even loss) of the forearm rotational function. Also, because of the special structure of the ulnar radius with two parallel bones, problems such as osteofascial compartment syndrome may occur in the event of an injury. Therefore, if you have an injury or fracture of the ulnar radius, you should go to the hospital for a thorough examination and treatment.