Longissimus Thoracis, Gross Anatomy, Posterior View

Description

Running longitudinally on either side of the spinous processes, the longissimus thoracis is isolated within the erector spinae mass as it ascends from the lumbar region toward the thoracic cage, with segmental slips reflecting its multilevel attachments. Medially it lies adjacent to spinalis, while iliocostalis occupies a more lateral column; together they form the paraspinal gutters flanking the vertebral column. Superiorly, the trapezius and rhomboid muscles span from the cervical and upper thoracic midline toward the scapulae, while the latissimus dorsi sweeps inferolaterally over the posterior thoracolumbar fascia. Clear bilateral symmetry supports side-to-side comparison. Segmented attachment detail matters because longissimus thoracis spans transverse processes and rib angles, so focal pain patterns and weakness track with specific thoracic levels rather than a generic “back strain.” Palpable tenderness along the paraspinal groove often reflects myofascial trigger points in the erector spinae group, and the same corridor is traversed during posterior approaches for thoracic instrumentation, laminectomy exposure, and placement of pedicle screws where muscle stripping can contribute to postoperative atrophy. It also aligns with contemporary regional anesthesia: the erector spinae plane block targets fascial planes deep to these muscles to modulate dorsal rami and thoracic pain. Use this posterior back view for gross anatomy labs, kinesiology instruction on trunk extension and lateral flexion, and surgical education materials discussing posterior thoracolumbar exposure or paraspinal compartment anatomy. It also fits rehabilitation handouts that correlate thoracic paraspinal pain with specific vertebral levels and rib landmarks. Anatomical accuracy verified by SciePro's Medical Advisory Board.