The manifestations and hazards of low muscle tone in babies are as follows: First, the manifestations, the baby’s weakness in sucking at the breast, the inability to smile at two months, the inability to laugh at four months, the inability to lift the head in the prone position, or the inability to hold the head upright in the sitting position, and the low muscle tone, which makes it difficult for the baby to maintain a vertical position and balance. When parents touch the baby’s muscles with their hands, the muscles feel abnormally soft, and there is also excessive movement of ligaments and joints, and the limbs have poor resistance to gravitational movement, for example, when parents lift the baby’s arms and let go, the arms will sag in the direction of gravity. Second, the harm, the baby’s poor motor ability, to a certain age can not lift the head, turn over, sit, crawl, stand, walk, some babies walking posture or grasp the posture of things will be different from normal children, serious babies can not even walk.