An Erb palsy is the most common injury of the neonate in a shoulder dystocia. The arm is typically limp and at its side with the arm internally rotated. If the palsy is severe, then the infant may not be able to move its fingers. Eighty percent of the time, brachial plexus injuries will improve with physical therapy. However, if the nerve roots are avulsed rather than simply injured, the neuropathy usually will not resolve.