Obliquus capitis inferior
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The obliquus capitis inferior is the most inferior located suboccipital muscle. Also, it is the only suboccipital muscle that is not attached to the skull. Instead, it connects the first cervical vertebra (atlas; C1) with the second cervical vertebra (axis; C2) and acts at the atlanto-axial joint. And finally, it forms the inferolateral border of the suboccipital triangle.