Medial Intertransversarii Lumborum Muscles (Right)
Musculi intertransversarii mediales lumborum
Read moreQuick Facts
Origin: Accessory processes of L1-L4 vertebrae.
Insertion: Mammillary processes of L2-L5 vertebrae.
Action: Assists in lateral flexion of the trunk.
Innervation: Anterior and posterior rami of lumbar nerves.
Arterial Supply: Dorsal branches of lumbar arteries and lateral sacral arteries.
Related parts of the anatomy
Origin
The medial intertransversarii lumborum muscles originate from the accessory processes of the first to fourth lumbar vertebrae.
Insertion
The fibers of the medial intertransversarii lumborum muscles travel inferiorly to the lumbar vertebrae that are located one vertebral segment inferior to their origin sites. They insert onto the mammillary processes of the second to fifth lumbar vertebrae.
Key Features & Anatomical Relations
Overall, the intertransversarii lumborum muscles are the more inferior of the three parts of the intertransversarii muscles. They are intrinsic muscles of the back.
The intertransversarii lumborum muscles are composed of many short individual muscles that are classified as belonging to either the:
- medial intertransversarii lumborum muscles;
- lateral intertransversarii lumborum muscles.
With regard to the medial intertransversarii lumborum muscles specifically, they are located:
- anterior to the multifidus muscles;
- medial to the lateral intertransversarii lumborum muscles.
Actions
The medial intertransversarii lumborum muscles assist in lateral flexion of the trunk to the same side during unilateral contraction. They also help stabilize the lumbar vertebrae (Moore, Dalley and Agur, 2009). They may also be involved in proprioception (Standring, 2016).
References
Moore, K. L., Dalley, A. F. and Agur, A. M. R. (2009) Clinically Oriented Anatomy. Lippincott Williams & Wilkins.
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.
