Name
Pronunciation
(SO-us MI-nor)
Origin/Proximal Attachment
Sides of bodies of T12 & L1 vertebra
Insertion/Distal Attachment
Pubic ridge
Action/Relevance
Weak flexor of the pelvis & lumbar spine
Innervation
Ventral ramus of the first lumbar nerve
Notes
Psoas minor is one of the muscles of the posterior abdominal wall. It is absent in 30-40% of the population.
It originates from the:
* vertebral bodies of T12 and L1
* intervertebral disc between T12 and L1
Passing inferiorly and slightly laterally with a long tendon, it inserts into the:
* fascia overlying the iliopsoas muscle
* pectineal line of the pubis
* iliopubic eminence
It is innervated by the anterior primary rami of the first lumbar nerve (L1).
Psoas minor has a weak action to:
* flex the pelvis
* flex the lumbar region of the vertebral column