The baby’s forearms love to rotate internally, which may be related to insecurity, brachial plexus nerve injury, cerebral palsy and other factors, and can be corrected by pacifying the baby, functional training, surgery and other ways. 1. Lack of security: some babies due to insecurity, the two small arms will be bent in front of the chest, if the baby normal milk, general condition is normal, no abnormal crying and so on, can consider this possibility. At this time, the mother should gently caress the baby to increase its sense of security, may be able to improve the baby’s posture. 2. Brachial plexus nerve injury: in the birth process, may damage the baby’s brachial plexus nerve, thus the forearm internal rotation may occur, within 6 months of the baby can be treated conservatively, will be placed on the upper arm in the abduction 90 ° external rotation position, elbow slightly flexed, palm up, palm to the face. With massage, physical therapy, acupuncture and other treatments. 6 months has not yet recovered should be surgical treatment. 3. Cerebral palsy: some babies may also show signs of internal rotation of the forearms, which may be accompanied by abnormal quietness, weakness in breastfeeding, unsatisfactory weight gain, etc. EEG, cranial CR, MRI, etc. may be perfected to assist in the diagnosis, and if the diagnosis is clear, it is necessary to start the functional exercises as early as possible, together with electrotherapy, hydrotherapy and hyperbaric oxygen, and if necessary, surgical treatment. Forearm internal rotation in babies can be seen in a variety of conditions, it is recommended to consult a specialist for evaluation and treatment in order to avoid delays in the condition.