Your brachial plexus is a network of nerves in your shoulder that branches into five major nerves in each arm. It carries signals from your spinal cord to your arms and hands, allowing you to move your arm, hands, and wrists. Sensory skin nerves are also part of the brachial plexus and allow you to feel temperature and other sensations. There are several types of brachial plexus injuries, with many different causes. They also vary in severity, with some people healing completely on their own and others having permanent damage.