Intertransversarii Laterales Lumborum, Posterior View

Description

Running between adjacent lumbar transverse processes, the intertransversarii laterales lumborum appear as short segmental muscle slips positioned lateral to the intertransversarii mediales and deep to the erector spinae mass. A posterior view also brings the lumbar spinous processes and laminae into alignment at midline, with the multifidus filling the groove between spinous processes and transverse processes, and the quadratus lumborum sitting farther lateral between the iliac crest and the 12th rib. Inferiorly, the sacrum and posterior iliac crests frame the lumbosacral junction. Small muscles. Big teaching value. The intertransversarii laterales are most often discussed in the context of lumbar segmental control, where their proximity to the zygapophysial joints and intertransverse spaces makes them a useful reference when explaining coupled motion during lateral flexion and the fine adjustments required in upright posture. For clinicians and proceduralists, this posterior anatomy also helps orient the relationship between deep paraspinal layers and the bony landmarks used during lumbar medial branch blocks or radiofrequency ablation for facet-mediated pain, where needle trajectories pass through the paraspinal musculature toward the transverse process and superior articular process region. Faculty can drop this plate into gross anatomy lab manuals when introducing the deep back of the lumbus after removing erector spinae, or into spine modules for physical therapy and sports medicine programs that emphasize segment-by-segment stabilization. It also suits surgical atlases and CME materials that need an accurate posterior layer-by-layer map of lumbar musculature for approach planning and for interpreting postoperative paraspinal atrophy on follow-up imaging. Anatomical accuracy verified by SciePro's Medical Advisory Board.