Internal Oblique Muscle
Longissimus Thoracis Muscle
Attachments of Longissimus Thoracis: Origin & Insertion
Origin: Transverse and spinous processes of lumbar vertebrae; sacrum and iliac crest via iliocostalis lumborum tendon & lumbosacral aponeurosis.
Insertion: Transverse processes of T1 – T12; between tubercles and angles of lower 9 to 10 ribs.
Actions of the Longissimus Thoracis Muscle:
- Bilateral action: extends and hyperextends vertebral column (back).
- Unilateral action: laterally flexes vertebral column to the same side.
Nerve Supply to Longissimus Thoracis:
- dorsal rami of the thoracic and lumbar spinal nerves.