When both radius and ulna are dislocated, the forearm is bent nearly at a right angle, and is immovable. When the ulna alone is dislocated, there is a tumor projecting posteriorly, the elbow is bent at right angles, and the forearm is turned upwards. The radius is dislocated at the elbow either forwards or backwards. When backwards the head of the bone forms a prominence behind, the arm is bent and the hand prone. When fowards there is a distinct prominence in front, the arm is slightly bent, and the hand supine.

TREATMENT. -- When both bones are dislocated, or in case the ulna is alone out of joint, make forcible extension of the forearm over your knee, placed at the elbow, to make counter-extension. Then bend the forearm while making extension, and reduction will take place. In forward dislocation of the radius make forcible extension, and while doing so, turn the hand from without inwards, called pronation. In backward dislocation make forcible extension, and turn the hand from within outward, or supination. In either case you should press the head of the bone into proper position with your thumb. Then advise rest, cold applications, and a sling.