Ligament · Neck

Alar ligament

Ligamentum alare

A pair of short, exceptionally strong cords running from the sides of the tip of the dens — the peg of bone rising from the second neck vertebra — upward and outward to the inner surface of each occipital condyle, either side of the foramen magnum. They connect the skull directly to the axis, bypassing the atlas between them. Because they are anchored off the midline, turning the head to one side winds the opposite ligament tight, and that winding is what ends the movement: the alar ligaments, not muscle, set the outer limit of how far the skull can rotate and side-bend on the neck.