Trunk (thorax, abdomen, back)

Lateral Intertransversarii Lumborum

Musculi intertransversarii laterales lumborum

Origin

Transverse process (and accessory process) of a lumbar vertebra (L1-L4)

Insertion

Transverse process of the lumbar vertebra below (L2-L5)

Function

Unilaterally: lateral flexion of the lumbar spine. Bilaterally: segmental stabilization

Innervation

Ventral rami of the lumbar spinal nerves

Movement & chain

Contributes, together with quadratus lumborum, to lateral bending and segmental control of the low back during asymmetric loading.

Palpation

Deep between lumbar transverse (costiform) processes; cannot be isolated manually.

Clinical

Aid lateral lumbar flexion and segmental proprioceptive stabilization; contribute to deep lumbar muscular stability.

Segmental innervation

Ventral rami L2-L5.

In clinical practice

Ergonomic patient repositioning (log-roll technique in spinal trauma) and pressure offloading; maintain neutral spinal alignment in bedridden patients.

Region in the model

Trunk (thorax, abdomen, back)