Bunions are most common in infants, and they usually disappear in 3-4 months, with some time variations in different infants, which is normal and not a cause for concern. Newborn children, the flexor muscle is too tense, will cause the phenomenon of the thumb buckle, in medicine known as the grip reflex, is a normal physiological phenomenon, usually with the child’s age, the body gradually grows and develops as well as the change of muscle tone, the flexor muscle tension will have a significant decline, when the extensor muscle function plays a dominant role, this phenomenon will gradually disappear. If, after 3 to 4 months, the infant still has an inward thumb that cannot be straightened smoothly and needs help, he or she may be suffering from stenosing tenosynovitis of the thumb, which is mainly due to edema produced by friction between the tendon sheath and the tendon, resulting in joint restriction. If the symptoms persist for a long time, it is recommended to go to the regular hospital in time, under the guidance of the doctor, relevant examination, according to the results of the examination, take targeted treatment.