Erb's Palsy is a form of brachial plexus injury.
   
    The brachial plexus is the network of nerves which control the muscles in the shoulder, arm and hand. The brachial plexus is located at the base of the neck on each side.  Injury to the nerves of the  brachial plexus can result in permanent paralysis or weakness of the shoulder, arm and hand resulting in a flaccid, limp arm and hand.

    The most common cause of a brachial plexus injury is excessive and improper traction on the baby's head during delivery. Such traction usually occurs when a physician simply pulls too hard on the baby's head, frequently in the presence of a shoulder dystocia (shoulder dystocia simply refers to the situation where the child's shoulder becomes stuck behind the pubic bone as the child descends down the birth canal).  When shoulder dystocia occurs, the child stops coming down the birth canal.  At that point, the shoulder must then be gently manipulated and released to allow the vaginal birth to continue or, as an alternative, a c-section must be performed.

    Excessive traction (i.e. pulling) on the baby's head causes injury to the nerves of the brachial plexus by either stretching the nerves or such traction can actually tear the nerves in two.

    Since the most common cause of brachial plexus injury is excessive traction, the injury is often avoidable by the use of only gentle traction in the presence of a shoulder dystocia or by reverting to a c-section delivery to avoid traction altogether.  The American College of Obstetricians and Gynecologists recommends that, when a shoulder dystocia is recognized, the physician and nurses must not apply any fundal pressure (pressure at the top of the uterus) and must avoid pulling excessively on the child's head. Violation of either of these recommendations is negligence by the doctor and nurses.

    In some circumstances, it is foreseeable before the delivery that the infant is large and therefore at risk for a shoulder dystocia.  In those instances, shoulder dystocia (and the risk of a potential brachial plexus injury) may be avoided by foregoing any attempt of a vaginal delivery and proceeding instead with a c-section delivery.

    The prognosis for brachial plexus injury depends upon the severity and extent of the nerve injury.  Surgery to repair or reconnect stretched and torn nerves can, in some instances, restore muscle control and allow for improved shoulder, arm and hand function.  Such nerve surgery is most effective when performed early, between five and twelve months of age.  However, even with ongoing therapy and surgery, complete recovery from a brachial plexus injury might not occur.