What Is the Brachial Plexus Nerve?

A nerve plexus is an area where nerves split and come back together. The brachial plexus (also called the brachial nerve plexus) is a group of nerves that start in the middle to lower neck, run under the collar bone and armpit, and then down the arm.

Anatomy

• The brachial plexus begins with five root nerves, one each on the fifth, sixth, seventh and eighth neck vertebrae and first upper back vertebrae. After these nerves split and come back together several times, the result is three nerves that run down the arm: the median, ulnar and radial nerves.

Purpose

• The nerves of the brachial plexus control muscle movements and feeling in the shoulder, arm and hand.

Injuries

• Brachial plexus injuries can cause numbness, tingling, pain, weakness or limited movement in the shoulder, upper arm, forearm and hand.

Muscle Compression

• In addition to direct injury to the brachial plexus, the nerves can be compressed by tight muscles in the neck and upper chest, causing thoracic outlet syndrome, which is pain in the neck and shoulder, numbness and tingling of the fingers, and a weak grip.

Brachial Plexus Palsy

• Brachial plexus palsy is caused by injury to the brachial plexus during birth. The Brachial Plexus Palsy Foundation offers support to families dealing with this condition.