If your baby has been diagnosed with a shoulder injury, what’s called an Erb’s palsy, you may be asking yourself, “How did that happen? Why did my baby’s shoulder and arm get injured?” During labor and delivery the baby comes down the birth canal, and at that point the baby comes in contact with mom’s pelvic bone. If the baby is too large, the baby’s shoulder gets stuck against the pelvic bone, and at that point there are two choices. The doctor can deliver the bay by Cesarean section, or some doctors decide they would rather try to use forceps or a vacuum to pull the baby through the birth canal. That’s where the Erb’s palsy injury occurs. As the doctor is pulling on the baby’s head, the baby’s shoulder is being pressed against mom’s pelvic bone — stretching the nerve and sometimes causing severe injury to the baby’s arm, to the point where the child will have a palsied arm for the rest of the child’s life.