Anatomy 101: Brachial Plexus

The brachial plexus is a group of nerves that stem from the spinal cord in the neck and travel all the way down the arm. These nerves control the muscles of the shoulder, elbow, wrist and hand. They also provide feeling in the arm.

It starts with the five “roots” at the neck. The second level is called “trunks,” which continue toward the shoulder then divide into the third layer of two nerves called the anterior division and the posterior division. The nerves in the fourth layer are called “cords,” and the final layer is comprised of the “branches” that feed the shoulder and arm. See the image below for details.

An injury to the brachial plexus can be minor but can also be very serious, causing permanent damage to arm function. You can damage these nerves with stretching, pressure or cutting. This can happen in many different ways such as a serious fall, a car accident or a broken bone. Because nerves are connected to the brain, injuring the brachial plexus can prevent you from using your hand or arm. Visit a hand surgeon or the emergency room right away if you can’t feel anything in the hand/arm area. Recovering from a brachial plexus injury can take months. Getting treatment from a hand surgeon early on is extremely important. Your injury may be healed with therapy, or you may need surgery.