The biventer cervicis muscle is the dorsomedial division of semispinalis capitis that originates from the thoracolumbar fascia or thoracic vertebral transverse processes, and courses superficial to mutifidi muscles to insert on occipital bone.
Origin: Transverse processes of the fourth through second thoracic vertebrae.
Insertion: Occipital protuberance.
Action: Raises the head and neck, in unilateral action to flex the head and neck laterally.
Nerve: Dorsal branches of the cervical nerves