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