Newborn brachial plexus injuries: The twisting and extension of the fetal head as contributing causes.

The exact mechanism of the causation of brachial plexus injury (BPI) has long been a matter of controversy. It is our opinion that the twisting and the extension of the fetal head, during the labour and delivery process, will increase the stretching of the neck, thus contributing to the labour forces as the cause of BPI. Our opinions are offered to other researchers and readers for their consideration of how the labour forces can cause BPI.