If the thumb of a small baby is inwardly folded in the palm, this is called the cortical thumb sign, is an abnormal phenomenon, can be corrected by the following methods: 1, massage the thumb, parents hold the child’s wrist with one hand, the other hand will be inwardly folded thumb in the direction of extension to do massage, each time after massage, fixed baby’s thumb to maintain the extended state for 30 seconds (Figure 1), repeated massage, 2 ~ 3 minutes, several times a day; 2, during the day when the baby in the During the day, when the baby is awake, use a toy like a small scented coke in the palm of the hand, and make the baby hold the toy with the thumb and other fingers to stop the thumb from closing (Figure 2); 3, during sleep, wrap a handkerchief around the root of the thumb to help separate the thumb and palm, and tie a knot on the other side of the wrist to prevent the thumb from closing (Figure 3). If parents suspect that their baby has an ingrown thumb, it is recommended that they take their baby to a regular medical institution for diagnosis and correction under the guidance of a medical professional!