The accessory nerve is the eleventh cranial nerve. It attaches to the pairs of muscles that surround the neck that, for example, turn the head and shrugging the shoulders. In a physical examination, the health of the nerve can be tested by seeing how strong the muscles are when performing these movements, both with no resistance and against resistance. When a patient cannot move through the full range of motion or has little strength, it usually suggests damage to the accessory nerve. The nerve is rarely damaged by trauma, but it is not uncommonly damaged by surgery.