American Family Physician

P eripheral nerve injury in the upper extremity is common, and certain peripheral nerves are at an increased risk of injury because of their anatomic location. Risk factors include a superficial position, a long course through an area at high risk of trauma, and a narrow path through a bony canal. The anatomy and function of upper extremity nerve roots, as well as specific risk factors of injury, are described in Online Table A. The most common nerve entrapment injury is carpal tunnel syndrome, which has an estimated prevalence of 3 percent in the general population and 5 to 15 percent in the industrial setting. Given the potential for longstanding impairment associated with nerve injuries, it is important for the primary care physician to be familiar with their presentation, diagnosis, and management.