The brachial plexus is a system of nerves that leads signals from the spinal rope, which is housed in the spinal waterway of the vertebral segment (or spine), to the shoulder, arm and hand. These nerves start in the fifth, 6th, seventh and eighth cervical (C5–C8), and first thoracic (T1) spinal nerves, and innervate the muscles and skin of the mid-section, shoulder, arm and hand. Brachial plexus wounds, or injuries, are brought on by harm to those nerve.
Signs and symptoms may include a limp or paralyzed arm, lack of muscle control in the arm, hand, or wrist, and lack of feeling or sensation in the arm or hand. Although several mechanisms account for brachial plexus injuries, the most common is nerve compression or stretch. Infants, in particular, may suffer brachial plexus injuries during delivery and these present with typical patterns of weakness, depending on which portion of the brachial plexus is involved. The most severe form of injury is nerve root avulsion, which results in complete weakness in corresponding muscles. This usually accompanies high-velocity impacts that occurs during motor vehicle or bicycle accidents.