In China, congenital hip dysplasia was the previous term, but now the medical term has been changed to developmental hip dysplasia, or developmental hip dislocation. Careless parents often do not easily notice hip dislocation until their children walk, and only after they start to walk or even run away will they notice that their children have a ducking or swaying gait, and only then will they realize that their children are not the same as other children. This is because one side of the hip joint dislocation causes the hip abductor muscle on the affected side to be weak, resulting in a swaying back and forth when walking or running. This swaying gait is more pronounced in bilateral hip dislocations, which is a good indicator of developmental hip dislocation in children.