< Back to Previous Page Brachial Plexus Erb's Palsy Injury Brachial palsy is a paralysis or weakness of the arm caused by damage to the brachial plexus (the collection of nerves around the shoulder). Causes, incidence, and risk factors: Brachial nerve injuries can occur during a difficult delivery. For example, it can occur if the infant's head and neck are pulled toward the side as the shoulders pass through the birth canal. The condition can also be caused by excessive pulling on the shoulders during a vertex delivery (head first) or by pressure on the raised arms during a breech delivery (feet first). The infant may have varying degrees of arm paralysis: Brachial plexus injuries typically affect only the upper arm Erb's paralysis affects the upper arm and rotation of the lower arm Klumpke paralysis affects the hand (the infant may also have an eyelid droop on the opposite side) Brachial palsy is less common now that delivery techniques have improved and there is more use of C-sections when needed (where the baby is removed surgically through the abdomen). Risk factors include a larger than average newborn, shoulder dystocia, and breech delivery. Arm and shoulder fractures can also affect newborns who have had a difficult delivery. Fractures can cause pseudoparalysis. The symptoms may be very similar, although the long-term outlook is very different. Symptoms    Noticed immediately or soon after birth Lack of spontaneous movement in the upper or lower arm or hand Grip may be decreased on the affected side Moro reflex is absent on the affected side Normal arm position (arm flexed at elbow and held against body) may be absent or weak on affected side