Longissimus Thoracis Anatomy: Origin, Insertion, Actions, Innervation

Longissimus Thoracis Anatomy Study

Longissimus thoracis muscle connects the vertebra to the ribs.

The longissimus thoracis is also known as longissimus dorsi

Origin: Blended with Iliocostalis lumborum, from the posterior surfaces of the transverse processes of all the lumbar vertebrae and the thoracolumbar fascia
Insertion: Tips of the transverse processes of all thoracic vertebrae and lower nine or ten ribs, between the tubercle and angle.
Action: Extension of the thoracic spine, lateral flexion of the thoracic spine, extension of the lumbar spine, lateral flexion of the lumbar spine
Innervation: Dorsal primary rami of T1 to L5
Blood Supply: Dorsal rami of the posterior intercostal arteries

 

 

Primary Actions of the Longissimus Thoracis:

1. Extension of the thoracic spine when acting bilaterally

  • Agonists: Iliocostalis Cervicis, Iliocostalis Thoracis, Iliocostalis Lumborum, Longissimus Cervicis, Spinalis Thoracis, Semispinalis Cervicis, Semispinalis Thoracis
  • Antagonists: Rectus abdominis

2. Lateral flexion of the thoracic spine when acting unilaterally

  • Agonists: Iliocostalis Cervicis, Iliocostalis Thoracis, Iliocostalis Lumborum, Longissimus Cervicis, External Oblique, Internal Oblique
  • Antagonists: Iliocostalis Cervicis, Iliocostalis Thoracis, Iliocostalis Lumborum, Longissimus Cervicis, External Oblique, Internal Oblique on the opposite side

3. Extension of the lumbar spine when acting bilaterally

  • Agonists: Iliocostalis Lumborum, Spinalis Thoracis
  • Antagonists: Rectus Abdominis

4. Lateral flexion of the lumbar spine when acting unilaterally

  • Agonists: Iliocostalis Lumborum, Psoas Major, Quadratus Lumborum, External Oblique, Internal Oblique
  • Antagonists: Iliocostalis Lumborum, Psoas Major, Quadratus Lumborum, External Oblique, Internal Oblique on opposite side

For pain and symptom information see: Longissimus Thoracis Pain and Symptoms


Recommended Anatomy Books

coloring_book
The Anatomy Coloring Book is one of the best study and reference books for beginning anatomy students. The diagrams are clearly labeled and allow you to see the relationship and placement of the various structures of the body. You will also be surprised how the act of coloring will help with recall. But this is not just a beginners book, it is also great for practitioners and therapists to have on hand to use with clients and patients to use as a visual reference.


References:

The Trigger Point Therapy Workbook – Claire Davies, Amber Davies, and David G. Simons

Basic Clinical Massage Therapy: Integrating Anatomy and Treatment – James H. Clay and David M. Pounds

Trigger Point Therapy for Myofascial Pain – Donna Finando and Steven Finando

Massage Therapy Principles and Practice – Susan Salvo

Theory & Practice of Therapeutic Massage – Mark Beck

 

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