Jeff Guzman at Napoli Bern in NY posts about the release of the most recent edition of Child Neurology which argues that, contrary to claims by obstetricians, the majority of brachial plexus injuries do not occur in utero.
Jeff notes that most studies of brachial plexus injuries are done in adults, where injuries usually take several days to be apparent via EMG.
However, the textbook of Child Neurology points out that the hypothesis is based upon the faulty assumption that infant and adult nerves act similarly. They do not. An infant’s nerve fibers are shorter. Consequently, it takes dramatically less time for an injury to become apparent.
Nice research by Jeff and great information about brachial plexus injuries.