Waist stool is a reclining stool tied to the waist of adults to use a new parenting tool, compared to directly holding the baby, with the waist stool can relieve the burden on the arms and shoulders of mothers and fathers. For babies over 4 months old can be used at your discretion, but for babies under 4 months old, lumbar stools need to be used with caution. From the baby’s spine development, the baby was born with no curvature of the spine, at about 3 months cervical convexity, able to lift the head, 4-5 months can use both hands to support the whole body, the baby into a sitting position, able to sit alone for a while, until 6-7 months when the thoracic spine convexity, the baby can sit steadily. If premature use of waist stool, especially for babies under 4 months is harmful, when the baby’s neck back waist strength is insufficient, the normal shape of the spine has not yet formed, can not withstand the pressure of sitting, it is best not to use the waist stool, otherwise it will affect the development of the baby’s spine, and even make the cervical spine deformation or abnormal development. Baby sitting on the waist stool, to ensure that the baby’s legs naturally open outward to form the M-shaped, in order to prevent hip dislocation and the formation of “O” leg, too small for the baby, the hip joint is not stable, sitting on the waist stool posture is easy to stretch the joint, and ultimately the risk of disability.