1. Injuries of the sternum from flexion-compression violence are described and contrasted with injuries from direct violence. The characteristic feature of flexion-compression injuries is a dislocation or fracture at or near the manubrio-sternal joint with backward displacement of the manubrium. 2. Treatment is outlined, with special reference to the indications for open reduction and wire fixation. 3. The mechanism of flexion-compression injuries of the sternum is discussed. The opinion is expressed that most of the force is transmitted to the sternum by the ribsâespecially the upper ribs.