Psoas Minor Muscle Beneath the Skin, Anterior View

Description

Visible beneath the anterior body wall, the paired rectus abdominis forms a vertical column on either side of the linea alba, while the external and internal oblique layers sweep inferomedially along the lateral abdomen. Deep to these layers, the psoas major lies anterolateral to the lumbar vertebral bodies, and the psoas minor, when present, runs on the anterior surface of psoas major as a narrow fusiform belly that tapers into a long, slender tendon. That tendon descends inferiorly toward the pelvic brim to blend with the iliopubic eminence and pectineal line via the iliopsoas fascia, positioned medial to the iliacus in the iliac fossa. Major retroperitoneal vessels, including the abdominal aorta and inferior vena cava, course centrally with close relationship to the medial borders of the psoas muscles. A small muscle. Easy to miss. An anterior, subcutaneous perspective on psoas minor matters because it is a variable structure and a frequent source of labeling errors in teaching, imaging correlation, and operative dictation. Its long tendon across the pelvic brim can mimic a fascial band or be mistaken for part of psoas major on cross-sectional anatomy, and it sits in the same neighborhood used as a landmark when describing lumbar plexus relationships within or along psoas major. Clinically, tendinous strain or irritation of the iliopsoas fascia can produce anterior groin pain that is hard to separate from iliopsoas bursitis or hip joint pathology on exam alone. Use this artwork in gross anatomy and kinesiology teaching when you want students to compare psoas major, iliacus, and the often-absent psoas minor, and to anchor their understanding of the pelvic brim and iliopsoas fascia in anterior topography. It also fits well in surgical education and radiology texts that discuss retroperitoneal approaches to the lumbar spine, anterior hip pain differentials, and anatomic variants relevant to CT and MRI interpretation. Anatomical accuracy verified by SciePro's Medical Advisory Board.