Longissimus

The longissimus muscle is the intermediate and the largest of the three columns, it has three parts with different origin and insertion:

  longissimus thoracis originates from the sacrum, spinous processes of the lumbar vertebrae and transverse process of the last thoracic vertebra and inserts in the transverse processes of the lumbar vertebrae, erector spinae aponeurosis, ribs and costal processes of the thoracic vertebrae.
  longissimus cervicis originates from the transverse processes of T6-T1 and inserts in the transverse processes of C7-C2.
  longissimus capitis originates from the transverse processes of T3-T1 runs through C7-C3 and inserts in the mastoid process of the temporal bone.