Longissimus Thoracis Muscle as, Posterior View

Description

Running longitudinally along the posterior thoracic wall, the longissimus thoracis forms the lateral column of the erector spinae, positioned lateral to spinalis thoracis and medial to iliocostalis thoracis. Muscular bundles rise superiorly from the thoracolumbar region toward the upper thorax, lying posterior to the ribs and transverse processes and deep to the superficial back musculature that would normally cover it in a full-layer dissection. Adjacent bony landmarks include the spinous processes and transverse processes of the thoracic vertebrae, the posterior ribs, the scapulae laterally, and the posterior iliac crests and sacrum inferiorly. Bilateral symmetry is clear. Posterior exposure of longissimus thoracis matters when you need to explain extensor mechanics and segmental stabilization across the thoracic spine, where rib attachments and facet orientation limit flexion but allow coupled rotation. Electromyography studies and clinical exams often treat the erector spinae as a unit, yet longissimus thoracis is a frequent pain generator in thoracolumbar junction strain and in myofascial trigger points that refer pain along the paraspinal line and into the posterior ribs. This is also the muscle surgeons and interventionalists traverse or retract during posterior thoracic approaches, and it provides a practical orientation for locating the medial branch targets used in facet joint denervation. Ideal for gross anatomy lab guides, kinesiology and biomechanics teaching, and spine-focused chapters in rehabilitation and orthopedic texts where readers need the erector spinae columns named and spatially anchored to vertebrae and ribs. It also supports patient-facing education on posture training, paraspinal strengthening, and thoracolumbar overuse injuries in sports medicine and physical therapy clinics. Anatomical accuracy verified by SciePro's Medical Advisory Board.