origin:
C7 and
T1-T6 thoracic transverse processes and articular
processes of 4th, 5th, and 6th cervical vertebrae;
insertion: between superior and inferior nuchal lines of the occipital;
action: extnesion of lateral flexion of the neck and head, and rotates it
to the opposite side;
nerve supply: posterior rami of the cervial nerves;
synergists: splenius group,
Semispinalis Cervicis ;