A Primer on Erb's Palsy for the Lay Person
Erb's Palsy is a nerve injury that effects the movement of a baby's shoulder, arm, wrist, and hand. It occurs in 0.5%-1% of all births.
Typically, Erb's Palsy results when too much force is applied to the baby's head while trying to pull out a baby whose shoulder is stuck in the birth canal. The baby may be too large to fit easily through the birth canal. When the baby's shoulder gets stuck in the birth canal, it is called "shoulder dystocia."
Pulling on the baby's head when the baby is stuck, stretches and injures the nerves in neck on the side of the stuck shoulder, that provide movement to the arm, hand, wrist, and fingers. This collection of nerve fibers is called the "brachial plexus," or "Erb's Point" (hence the name Erb's Palsy, or Brachial Plexus Palsy).
When it was first identified in the 1800's, Erb's Palsy was originally called "Obstetrical Palsy," because its relationship to traumatic birth was clear. However, doctors did not like having an injury named for their treatment, and so the name was changed to Erb's Palsy (or Brachial Plexus Palsy), so the connection between the injury and obstetrics was obscured.