Unusual Brachial Plexus Injury Caused by a Personal Watercraft Fall.

Brachial plexus injuries after personal watercraft accidents have been rarely reported. We present a 38-year-old female who was riding a personal watercraft when she was struck by an ocean wave and ejected backwards. The motor exam demonstrated bilateral upper extremity weakness. Brachial plexus MRI revealed left C4-C5 and C5-C6 nerve root sleeve tears, with possible similar contralateral injuries. The patient was observed for two days without clinical improvement and was sent home with an appointment to the peripheral nerve clinic and evaluation with a physiatrist. She completed six weeks of physical therapy, achieving substantial improvement, and recovered completely six months later. Traction of the brachial plexus can occur when an individual hangs onto the handlebars with the involved arm while being ejected from a personal watercraft. The expulsion causes a forceful separation motion of the shoulder with respect to the arm or the head with respect to the neck.