Subluxation of the head of the radius (subluxation of the head of the radius) occurs most often in children under 5 years of age. In children, the anterior and inferior aspect of the annular ligament of the humeroradial joint is weak, and the articular surface of the head of the radius is slightly posteriorly distal to the longitudinal axis of the radial stem, which is not completely perpendicular to the longitudinal axis of the radial stem and is ovoid in shape. In the posterior rotated position, the sagittal diameter is longer, and in the extreme anterior rotated position, the lower head of the radius slightly leaves the radial notch of the ulna, and its anterolateral edge is low and flat and located at the distal end, so that when the forearm is rotated anteriorly and the wrist is pulled with force, the annular ligament is prone to slipping towards the proximal end of the anterolateral aspect of the head of the radius. Its weak point is easily torn transversely, and the anterior aspect of the radial tuberosity is dislocated anteriorly and inferiorly to the anterior aspect of the annular ligament. With age, the weak attachment point of the annular ligament gradually thickens and strengthens, so it is not easy to dislocate! 1, usually pull (lift) the child’s hand, should pull the sleeve at the same time. 2, to prevent falling. 3, adults and children should pay attention to the method, not a single pull (lift) hand. 4, if the above performance, parents can reset by themselves, if unsuccessful, then should go to Quanzhou Children’s Hospital Pediatric Surgery. 5.Avoid repeated dislocation, the formation of habitual. 6.When wearing clothes, should avoid hand rotation anterior position pulling, should be and sleeve pulling at the same time.