The semispinalis capitis is a muscle located in the back of the neck. It is part of the semispinalis group, which includes other muscles that help with head and neck movement. This muscle originates from the upper thoracic and lower cervical vertebrae and inserts into the skull, specifically the occipital bone. Functionally, the semispinalis capitis aids in extending and rotating the head. It plays a crucial role in maintaining posture and allowing for smooth movements of the neck. Proper functioning of this muscle is important for activities such as looking up or turning the head side to side.