The intertransversarii connect adjacent transverse processes throughout the cervical and lumbar spine, acting as intersegmental lateral flexors and — more importantly — as proprioceptive monitors of lateral vertebral position. They have a high muscle spindle density similar to the rotatores and contribute to the continuous sensorimotor feedback necessary for fine spinal segment control. Their bilateral co-contraction contributes to intersegmental compression and stability.
| Origin | Transverse processes of each vertebra throughout the cervical and lumbar spine |
|---|---|
| Insertion | Transverse process of the adjacent vertebra above |
| Nerve Supply | Posterior and anterior rami of spinal nerves at each level |
| Blood Supply | Spinal arteries |
| Actions | Ipsilateral lateral flexion of individual vertebral segments; Proprioceptive stabilisation of individual motion segments |
|---|
Their primary function is proprioceptive feedback about lateral position of individual vertebral segments rather than generating significant lateral flexion force, given their extremely short lever arms and small cross-sectional area.
Like the rotatores, the intertransversarii function primarily as position sensors and intersegmental stabilisers rather than prime movers. They are included in the functional anatomy of the deep segmental stabilising system alongside the multifidus, and their dysfunction contributes to impaired proprioception after spinal injury and in chronic low back pain.
Not individually palpable due to their deep position between transverse processes. Assessed as part of the deep intersegmental muscle system through clinical tests of spinal proprioception and segmental control.
Impaired intertransversarii and rotatores activity contributing to poor vertebral position sense after spinal injury, managed with proprioceptive retraining and deep segmental stabilisation exercises.
