The lumbar intertransversarii connect adjacent lumbar transverse processes and, like the rotatores, are thought to serve a primarily proprioceptive rather than motor role. Their proximity to the lateral branch of the lumbar dorsal ramus makes them relevant in medial branch block procedures for facet joint denervation. The medial intertransversarii lie adjacent to the target point of the medial branch block at each lumbar level.
| Origin | Transverse process of each lumbar vertebra (medial and lateral columns) |
|---|---|
| Insertion | Adjacent transverse process — spans a single motion segment |
| Nerve Supply | Ventral and dorsal rami (medial intertransversarii — dorsal rami; lateral — ventral rami) |
| Blood Supply | Lumbar arteries |
| Actions | Ipsilateral lateral flexion (single-segment contribution); Proprioceptive role — high muscle spindle density suggests a sensory function |
|---|
Medial branch neurotomy (radiofrequency ablation) for lumbar facet joint pain passes through the intertransversarii to reach the medial branch of the dorsal ramus at the junction of the superior articular process and transverse process — the standard target point.
Not palpable individually.
Lumbar intertransversarii traversed during medial branch block procedures targeting the dorsal ramus for facet joint pain diagnosis and treatment.
