Corpus: Intertransversarii muscles

The intertransversarii muscles are skeletal muscles that belong to the deep (autochthone) back musculature.

The intertransversarii muscles connect the transverse processes of adjacent vertebrae. These muscles are present in the cervical, thoracic, and lumbar regions.

2.1. Posterior intertransversarii muscles

In the cervical region, the posterior intertransversarii muscles originate from the posterior tubercles of the transverse processes of cervical vertebrae C1-C7. They insert one level lower on the transverse processes of cervical vertebrae C2-C7 and thoracic vertebra T1. These muscles also connect with the anterior intertransversarii muscles, which have migrated inward.

2.2. Intertransversarii thoracis muscles

In the thoracic region, there are typically three intertransversarii muscles in the caudal part. These muscles originate from the transverse processes of thoracic vertebrae T10-T12 and insert at the corresponding points on the transverse processes of vertebrae T11 and T12, as well as on the mammillary process of the first lumbar vertebra (L1).

2.3. Medial intertransversarii lumborum muscles

In the lumbar region, the medial intertransversarii muscles originate from the mammillary processes of lumbar vertebrae L1-L4 and insert one level lower on the accessory processes of vertebrae L2-L5.

2.4. Lateral intertransversarii muscles

The lateral intertransversarii muscles originate from the costal processes of lumbar vertebrae L1-L4 and attach one level lower to the costal processes of vertebrae L2-L5. Uniquely, the ventral branches innervate these lateral muscles.

As part of the erector spinae muscle group, the posterior intertransversarii muscles are innervated by the lateral branches of the posterior rami from the corresponding spinal cord segments.

The posterior intertransversarii muscles contribute to the lateral flexion (tilt) of the spinal column.