Accurate height measurement needs to pay attention to the “four same”: ① the same time, because after standing or sitting up, the vertebral space of the human spine will be compressed, morning and evening height will be different, the same time measurement to have comparability; ② the same measuring tape ③ the same measurer to measure the person, different people, the ruler card in the head of the tightness will be different; ④ the same child The standing method, shoes off, heels, hips, shoulders and head all against the wall, chest up, abdomen, waist as straight as possible, eyes flat, head not too tilted, otherwise the highest point of the head can not be measured. If you are measuring at home, take off your child’s shoes, put your heels, hips, shoulders and head all against the wall, use a triangular ruler or a hard book, put one side against the wall and the other side against the level of the child’s head, draw a line on the wall, you don’t need to measure the specific height, you just need to distinguish the difference with the previous month. Parents often say, “My child grew by 2cm last month, but he hasn’t grown at all this month?” This is mainly related to the measurement error, if you do the above “four with”, you will reduce the measurement error.