Psoas minor

The psoas minor (Latin: musculus psoas minor) is a long and slim pelvic muscle lying on the anterior aspect of the psoas major muscle. It is located deep within the posterior abdominopelvic wall. The psoas minor stretches between the vertebral bodies of Th12 and L1 vertebrae and pubis of the hip bone. Although the psoas minor does not form the iliopsoas muscle complex, it belongs to the iliopsoas muscle group. The psoas minor is present only in around 60% of the population.

Psoas minor
OriginVertebral bodies of T12 and L1 vertebrae
Insertion Iliopubic eminence, pectineal line
ActionTrunk flexion
InnervationAnterior ramus of spinal nerve L1
Blood supply Lumbar arteries, lumbar branch of iliolumbar artery

Origin

The psoas minor muscle originates from the vertebral bodies of the twelfth thoracic (Th12) and first lumbar (L1) vertebrae.

Insertion

The psoas minor inserts on the iliopubic eminence and pectineal line of the pubis.

Action

The psoas minor muscle provides flexion of the trunk.

Innervation

The psoas minor is innervated by the anterior ramus of the spinal nerve L1.

Blood supply

The psoas minor muscle receives arterial blood supply from the lumbar arteries and lumbar branch of the iliolumbar artery. The lumbar arteries arise from the abdominal aorta, while the iliolumbar artery is a branch of the internal iliac artery.