Erb’s Palsy refers to an injury to an arm where there is some type of nerve injury. A brachial plexus nerve that runs down the neck into the shoulder becomes injured as a result of a traumatic birth. The obstetrical complication is known as shoulder dystocia, which is when one of the shoulders becomes impacted in the birth canal. The obstetrician is required to employ certain maneuvers to disimpact that shoulder without injury to the baby. If the obstetrician does not handle that obstetrical complication correctly and applied excessive downward pressure or traction on the fetal head, this is when that injury occurs.