A brachial plexus injury can cause symptoms such as arm weakness, lack of reflexes, no or limited movement on one side, fingers kept in a clawed position, and abnormal muscle contractions. Special reflex tests and muscle evaluations can diagnose a brachial plexus injury. Symptoms can last days or months depending on the severity of the injury. However, most newborns regain the feeling and mobility of the affected limb over time, often with daily physical therapy.
A common cause of brachial plexus injuries in infants is damage to the area during a difficult labor and delivery. Injury to the bundle of nerves from pulling, tugging, or yanking the infant can occur, forcing the arm and shoulder to excessively stretch. This may happen if the infant lodges behind the mother’s pelvis and the doctor tugs on the baby’s arm, or in a breech birth when the doctor pulls on the legs and forces the baby’s arms to squeeze overhead. Improper use of birthing tools and use of excessive force can also cause infant brachial plexus injuries.