Proximal Attachment
Obliquus capitis superior arises by tendinous fibers from the superior surface of the transverse process of C1.

Distal Attachment
It broadens as it ascends to attach to the occipital bone between the superior and inferior nuchal lines, lateral to semispinalis capitis and overlapping the attachment of rectus capitis posterior major.  

Nerve Supply
It is supplied by the dorsal ramus of C1.

Action
When acting together, obliquus capitis superior extends the head on the neck; acting individually it laterally flexes the head on the neck to the same side.  It stabilizes the atlanto-occipital joint during movement.