Inferior nuchal line

Inferior nuchal lines are faint bony ridges that stretch sideways from the center of the external occipital crest, continuing on the squamous part of the occipital bone. They run parallel to the superior nuchal lines, which start from the external occipital protuberance and also extend sideways on the squamous part of occipital bone. At times, supreme nuchal lines may be located above the superior nuchal lines within the bony area of the scalp.

The area between the superior and inferior nuchal lines serves as a medial attachment point for the semispinalis capitis muscle, and laterally for the superior oblique muscle. The area below the inferior nuchal line offers medial attachment to the rectus capitis posterior minor muscle, and laterally to the rectus capitis posterior major muscles.