Arm on affected side shows adducted shoulder, extended elbow, pronated forearm, and flexed wristÑÓporterÕs tipÓ position; caused by disruption of upper roots (C5-C7) of brachial plexus due to acute, severe flexion of spine in opposite direction from side of injury. Condition can occur in motorcyclists who skid on crash helmet, in birth injuries, or in gun shots to shoulder.