origin: spinous process of C7 to T3, inferior half of ligamentum nuchae;
insertion: mastoid process and lateral portion of superior nuchal line;
action: acting bilaterally, extends and hyperextends the head and neck;acing unilateally, laterally flexes and rotates head and neck to
the same side;
nerve supply: lateral branches of the posterior rami of the middle and lower cervical spinal nerves;
synergists: splenius cervicis, Semispinalis capitis, semispinalis cervicis, superior portion of Trapezius