Baby thigh lines should exclude whether there is congenital hip dislocation, at home you can first make a simple judgment, the specific method is the baby lying flat on the bed, observe the measurement of the legs are equal, and then the baby down to see the baby’s hip lines on both sides of the asymmetry, the two legs flexed hip, flexed knee and outward expansion of the hip joint, under normal circumstances the outside of the knee can touch the bed, and the two sides of the symmetry, if not must go to the hospital to do hip ultrasound. Generally, hip ultrasound is done for babies under 6 months of age, and pelvic plain film is needed for babies over 6 months of age. If the stripes of the two thighs are not symmetrical and the legs have lengths often for this disease. However, some mild dislocations and subluxations are difficult to diagnose by simple manipulation. In addition, some babies are fat and have a lot of fat, so the length of the leg is also difficult to be determined. Asymmetrical thigh lines suggest a possible congenital hip dislocation, and many normal babies or children with brain injury also have asymmetrical thigh lines, so parents need to pay special attention to this.