origin: the transverse process of the 6th to 10 Thoracic vertebrae;
insertion: the spinous process of the 1st to 4th thoracic and 6th-7th cervical vertebrae;
action: extends the spine and rotates it toward the opposite side;
nerve supply: posterior rami of the thoracic nerves,
T1 to T6;
synergists:
Longissimus Thoracis , Iliocostalis thoracis,
Spinalis Thoracis
