The obliquus capitis superior is located above the neck and at the base of the back of the head, near the skull's occipital bone.
The muscle originates from the atlas bone's lateral mass (side) and it inserts into the inferior nuchal line. The atlas bone is also known as the first cervical vertebrae (C1); it is the uppermost vertebra of the spinal column. The inferior nuchal line is a ridge near the underside of the back of the skull where muscles attach.
The suboccipital nerve provides the muscle innervation (nerve supply) and a connection, ultimately, to the brain. The nerve emerges from the spinal column at the space between the atlas bone and the skull.
The muscle assists in moving the head. It extends the head, while also helping it to flex. The neck features two obliquus capitis superior muscles symmetrically located on the left and right sides. This muscle only assists in flexing the neck to the side on which it is located. These actions also involve the atlanto-occipital joint, which lies between the atlas and occipital bones.