Multifidus Muscle

Description

Running deep to the erector spinae, the multifidus is rendered as a series of short, segmental muscle bundles spanning adjacent vertebrae along the posterior cervical, thoracic, lumbar, and sacral regions in an adult male. Fascicles arise from mammillary processes in the lumbar spine, transverse processes in the thoracic spine, and articular processes in the cervical spine, then pass superomedially to insert onto the spinous processes one to four levels superior. Medially the bellies abut the spinous processes and laminae; laterally they blend with the rest of the transversospinalis group, sitting anterior to more superficial paraspinals. Layering is the point. Multifidus matters because it is the segmental stabilizer clinicians argue about and palpate badly. Atrophy and fatty infiltration, often seen on lumbar MRI after an acute episode of low back pain or after discectomy, correlate with impaired lumbopelvic control and poorer return-to-activity in some cohorts, and this view makes clear why re-education targets short-range control rather than gross trunk extension. The close relationship of these fibers to the zygapophyseal joints also helps explain why medial branch blocks and radiofrequency ablation address facetogenic pain without restoring the muscle’s stabilizing function. Use this artwork in spine anatomy teaching for gross anatomy, kinesiology, and rehabilitation courses to distinguish multifidus from longissimus and iliocostalis, and in textbooks or patient-facing material discussing segmental stabilization, post-operative paraspinal changes, and MRI patterns of paraspinal degeneration. It also fits surgical education modules that introduce posterior midline approaches and the muscular planes encountered during exposure. Anatomical accuracy verified by SciePro's Medical Advisory Board.