It is possible that hip dysplasia is a result of an asymmetrical leg pattern. The incidence of hip dysplasia is 4%-11.5%, about 95% is reversible, and only about 2% of hip dysplasia requires orthopedic treatment. If your baby finds asymmetry in the pattern of the left and right legs when lying on his or her back, you should pay more attention to the possibility of developmental hip dislocation. There are generally two types of leg pattern asymmetry: (1) Number asymmetry: one leg has 2 leg patterns and one leg has 3 leg patterns. (2) Position asymmetry: the baby turns over and finds that the two leg lines are asymmetrical in height after the legs are brought together. Not all leg pattern asymmetry is a problem, this situation is also more common in normal children, at the same time, even if the child’s leg pattern is symmetrical does not necessarily mean that there is no problem with the development of the hip joint, if both sides have problems with the development of the leg pattern may also be symmetrical. When asymmetrical leg lines are found, a pediatrician or orthopedic surgeon can be consulted for further examination. (1) During the examination, the baby is placed in the supine position, observe whether the lower limbs are equal in length, equal length is normal, unequal length of the lower limbs indicates possible unilateral hip dislocation. (2) In the lying position, bend the hip and knee and put both feet on the bed, if the height of both knees is equal, it is normal; in the case of single joint dislocation, the height of both knees is not equal, ultrasound examination or X-ray is needed.