The inflexibility of a 6-month-old baby’s hands may be caused by injury, cerebral palsy and other factors. 1. Injury: For example, cuts and external blows may cause damage to nerves or muscles. As the damage will cause pain and other symptoms, the child cannot move his/her hands freely, which will lead to inflexibility. 2. Cerebral palsy: it may be related to heredity, prematurity, ischemic-hypoxic encephalopathy and other factors, which may cause motor development disorders in children, leading to inflexibility of the hands, and in more serious cases, it may lead to mental retardation and impaired language development in the baby. 6 months baby hands are not flexible, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.