psoas major muscle

The psoas major is a long fusiform muscle placed on the side of the lumbar region of the vertebral column and brim of the lesser pelvis. It joins the iliacus muscle to form the iliopsoas. In less than 50 per cent of subjects the psoas major is accompanied by the psoas minor. [WP,unvetted]. Every claim on this page comes from the Leumas anatomy graph and carries its source.

What the psoas major muscle is

The psoas major is a long fusiform muscle placed on the side of the lumbar region of the vertebral column and brim of the lesser pelvis. It joins the iliacus muscle to form the iliopsoas. In less than 50 per cent of subjects the psoas major is accompanied by the psoas minor. [WP,unvetted]. The atlas records it as a muscle at the organ scale in the human body.

Where the psoas major muscle is

It sits within the muscular system. Positioned deliberately as part of this species body plan.

What the psoas major muscle connects to

The atlas records 5 typed relationships for it, across 5 kinds of connection. a kind of prevertebral muscle.

Supply and innervation

Innervation: lumbar nerve.

Also called

Also recorded as psoas major and m. psoas major. Searching any of those names reaches this page.

Source

Uberon multi-species anatomy ontology (Mungall et al.), CC BY 4.0. Term UBERON:0001298, version 2026-06-19, retrieved 2026-08-24. Licence: CC-BY-4.0.

• A kind of: prevertebral muscle.
• Innervated by: lumbar nerve.
• inserts into: lesser trochanter.
• originates from: transverse process of vertebra.
• antagonist of: gluteus maximus.

Questions

Where is the psoas major muscle?

It sits within the muscular system. Positioned deliberately as part of this species body plan.

What does the psoas major muscle connect to?

A kind of: prevertebral muscle.

Is the psoas major muscle the same in other species?

Leumas holds the same relationship vocabulary for every species it carries, so where another dataset records this structure you can put the two side by side on /compare.