Bony landmark · Head

Mastoid process

Processus mastoideus

The mastoid process is the hard cone of bone you can feel immediately behind the earlobe. It is the anchor for the sternocleidomastoid, the strap that runs down the front of the neck to the collarbone and breastbone, so it is pulled on every time the head turns or lifts. The splenius capitis and longissimus capitis attach just behind it and the posterior belly of the digastric on its inner side. Tenderness right on the bone here usually means the muscles pulling on it have been working too hard.