| The femoral nerve may run buried in a cleft of the iliacus under the psoas. |
| An accessory spine behind the ileopectineal eminence occasionally provides an attachment site for the psoas minor muscle. |
| The extension of muscle fibers onto the fascia of psoas or quadratus lumborum occurs occasionally. |
| The lateral cutaneous nerve of the thigh passes from the lateral border of psoas major across the iliac fossa to pierce the inguinal ligament. |
| The psoas and iliacus muscles are occasionally completely independent muscles. |
| The iliacus muscle, sharing a tendon with the psoas at the lesser trocanter, fans up and opens, lining the inside of each ilium. |
