Multifidus Muscle

Description

Running longitudinally along the posterior lumbar spine, the multifidus (musculus multifidus) appears as a segmented column of deep transversospinales lying medial and deep to the erector spinae mass. Individual fascicles span from mammillary processes and transverse processes to the spinous processes of more superior vertebrae, crossing the zygapophysial joints in a superomedial direction. Superiorly, the lower ribs frame the thoracolumbar junction, while inferiorly the muscle blends toward the dorsal surface of the sacrum and posterior iliac crest, sitting medial to the ilium and dorsal to the pelvic ring. Deep. Layered. Precise. A posterior deep-back view like this is the one you want when teaching segmental lumbar stability rather than gross trunk extension, because multifidus provides short-lever control of intervertebral motion where the erector spinae tend to dominate visually. Clinically, the muscle is often implicated in chronic low back pain, with atrophy or fatty infiltration seen on axial MRI after acute episodes and after lumbar surgery, and it can be injured during midline posterior approaches that strip paraspinal attachments from the spinous processes. The relationship to the lumbar spinous processes, laminae, and facet joints also matters during medial branch blocks and radiofrequency ablation planning, where needle trajectories and landmarks are interpreted relative to the paraspinal columns. Use this illustration in gross anatomy and kinesiology courses to distinguish the transversospinales from the erector spinae and to reinforce how multifidus spans multiple motion segments across the lumbar vertebrae and sacrum. It also fits well in spine surgery texts, pain medicine atlases, and rehabilitation materials discussing lumbar stabilization training and postoperative paraspinal changes. Anatomical accuracy verified by SciePro's Medical Advisory Board.