During birth, there are several ways the brachial plexus birth injury, a group of nerves that are located around the shoulder, may be injured or damaged. The brachial plexus refers to a group of nerves that are located around the shoulder. If these nerves are injured, weakness or a loss of mobility in the arm may result. https://www.malpracticeohio.com/birth-injuries/child/brachial-plexus/