Psoas Minor

Description

Running deep along the posterior abdominal wall, the psoas major is highlighted against the grayscale trunk and proximal thigh musculature, descending from the lateral aspects of the lumbar vertebrae toward the lesser trochanter of the femur. Medial to psoas major, the psoas minor, when present, appears as a slender fusiform belly with a long tendon, arising near T12 to L1 and coursing inferiorly over the anterior surface of psoas major to the iliopubic eminence and pectineal line via the iliopectineal arch. Superiorly, lower ribs and intercostal spaces frame the upper torso, while anterior abdominal wall landmarks such as rectus abdominis and the external oblique region remain superficial to the retroperitoneal psoas compartment. Proximally, the pelvis and upper femur establish the hip relationship. For teaching and operative planning, this anterior perspective clarifies why psoas minor is easy to miss and easy to misname, it is absent in a large proportion of adults and its tendon can be mistaken for fascia or the medial border of iliopsoas during dissection. Low back and groin pain syndromes are more often driven by psoas major or iliopsoas tendinopathy, yet psoas minor can contribute to the iliopsoas fascial plane and may be discussed in “psoas syndrome” differentials, along with entrapment considerations for the genitofemoral nerve that pierces psoas major. A small muscle, big confusion. Use this plate in gross anatomy labs to teach the variability of psoas minor and the anatomy of the loin region, or in physiotherapy and sports medicine materials contrasting hip flexor mechanics with lumbar stabilization claims. It also supports surgical education on anterior lumbar approaches and retroperitoneal corridor orientation in adult male anatomy. Anatomical accuracy verified by SciePro's Medical Advisory Board.