Superior Nuchal Line
The Superior Nuchal Line runs laterally from the external occipital protuberance toward the mastoid process of the temporal bone. The muscles attaching along this line are: semispinalis capitis, sternocleidomastoid, trapezius, and splenius capitis.
Neurosurgeons use the superior nuchal line as a surgical landmark for placement of occipital screws. To avoid endangering the cranial sinuses when performing occipito-cervical fusion the guideline for placement of the occipital screws is below this line.