Lateral Lumbar Intertransversarius (Musculus intertransversarius lateralis lumborum)
Educational content only — not medical advice.
Anatomy
A deep muscular slip bridging the transverse (costiform) processes of adjacent lumbar vertebrae, homologous to intercostal musculature. Unlike its medial counterpart which belongs to the intrinsic back muscles proper, the lateral intertransversarius is innervated by the ventral (anterior) rami of lumbar spinal nerves. It stabilizes the lumbar spine against lateral shear forces and executes lateral flexion of the lumbar segments.
Origin & insertion
Between the transverse (costiform) processes of adjacent lumbar vertebrae, spanning from L1 down to L5.
Action
Laterally flexes the lumbar vertebral column to the ipsilateral side; stabilizes adjacent lumbar vertebrae during gait.
Innervation
Anterior (ventral) rami of lumbar spinal nerves (L1–L4).
Clinical notes
Segmental spasm of the lateral intertransversarii contributes to acute antalgic lateral trunk tilt (sciatic scoliosis) observed in acute lumbar disk herniations.
Related structures
Educational references
FAQ
What is the role of the Lateral Lumbar Intertransversarius?
A deep muscular slip bridging the transverse (costiform) processes of adjacent lumbar vertebrae, homologous to intercostal musculature. Unlike its medial counterpart which belongs to the intrinsic back muscles proper, the lateral intertransversarius is innervated by the ventral (anterior) rami of lumbar spinal nerves. It stabilizes the lumbar spine against lateral shear forces and executes lateral flexion of the lumbar segments.
Why is the Lateral Lumbar Intertransversarius clinically important?
Segmental spasm of the lateral intertransversarii contributes to acute antalgic lateral trunk tilt (sciatic scoliosis) observed in acute lumbar disk herniations.
Source & license
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