Muscle · Neck

Longissimus capitis

Musculus longissimus capitis

The one part of the erector spinae that reaches the head. It is a narrow strap climbing from the upper thoracic and lower cervical vertebrae to the back edge of the mastoid process — the bony knob you can feel behind the ear — so it runs up the side of the neck rather than beside the midline like the semispinalis. Because it ends on the mastoid, well to the side of the joints it crosses, its pull draws the head backwards and towards its own side and turns the face that way too. It shares the mastoid with the sternocleidomastoid, which arrives at the same point from the front, so the two pull the head in opposite directions across the same landmark.