The Multifidus Muscle of a Male Viewed Closely

Description

Running in paired columns immediately lateral to the thoracic spinous processes, the multifidus is rendered in red as short, obliquely oriented fascicles that span from transverse processes and articular processes to the laminae and spinous processes of more superior vertebrae. Each bundle courses superomedially, creating a layered, interwoven pattern that thickens toward the midline over the vertebral arches, deep to the erector spinae. Superficial reference muscles of the upper back, including trapezius and latissimus dorsi, appear in gray, with the scapular margins and posterior ribs providing bony context lateral to the vertebral column. Segmental anatomy is the point. Multifidus matters because it is the most segmentally specific extensor and rotator of the spine and a primary stabilizer of individual motion segments through controlled tension across the zygapophysial joints and intervertebral discs. In chronic low back pain, multifidus atrophy and fatty infiltration are common findings on MRI, and targeted rehabilitation often aims to restore its function rather than simply strengthening the larger erector spinae. For surgeons, the muscle’s relationship to the laminae and facet joints frames common posterior approaches, where subperiosteal dissection and retraction can denervate or devascularize multifidus and contribute to postoperative pain and weakness. Faculty can drop this close view into a back or trunk module when teaching intrinsic back muscles, emphasizing how multifidus differs from longissimus and iliocostalis in fiber length, depth, and segmental attachments. It also suits atlas plates and spine surgery chapters discussing posterior exposure, facet joint landmarks, and interpretation of paraspinal changes on axial MRI or ultrasound-guided injection planning. Anatomical accuracy verified by SciePro's Medical Advisory Board.