Longissimus Thoracis (Left) (Musculus longissimus thoracis)
Educational content only — not medical advice.
Anatomy
The largest and longest intermediate component of the erector spinae, blending caudally with the iliocostalis lumborum in the erector spinae aponeurosis. It ascends along the thoracic vertebral column, splitting into lateral (costal) and medial (vertebral) slips that attach to all twelve ribs and adjacent transverse processes. It provides major extensor force to the trunk and restrains forward bending under load.
Origin & insertion
From the posterior surfaces of the lumbar transverse processes and thoracolumbar aponeurosis, into the tips of the transverse processes of all thoracic vertebrae and the lower nine or ten ribs.
Action
Powerful extensor of the thoracic vertebral column; laterally flexes the vertebral column to the same side.
Innervation
Posterior rami of thoracic and lumbar spinal nerves (T1–L5).
Clinical notes
Bilateral longissimus spasm produces rigid thoracic hyper-extension; unilateral contraction and chronic myofascial trigger points frequently complicate scoliosis.
Related structures
Educational references
FAQ
What is the role of the Longissimus Thoracis (Left)?
The largest and longest intermediate component of the erector spinae, blending caudally with the iliocostalis lumborum in the erector spinae aponeurosis. It ascends along the thoracic vertebral column, splitting into lateral (costal) and medial (vertebral) slips that attach to all twelve ribs and adjacent transverse processes. It provides major extensor force to the trunk and restrains forward bending under load.
Why is the Longissimus Thoracis (Left) clinically important?
Bilateral longissimus spasm produces rigid thoracic hyper-extension; unilateral contraction and chronic myofascial trigger points frequently complicate scoliosis.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details