Arises, down the midline, from the external occipital protuberance (inion), the nuchal ligament, the medial part of the superior nuchal line, and the spinous processes (spines) of the vertebrae 7th cervical and 12th thoracic vertebrae (C7-T12)
Lower part of the Nuchal Ligament, Spines of C7, and spines of first 5 Thoracic vertebrae.
Posterior tubercles of transverse processes of C1 - C4 vertebrae.
3rd to 5th ribs, near their costal cartilages.
Fleshy slips from the outer surface of upper 8 or 9 ribs.