Psoas Minor Muscle

Description

Running along the anterior lumbar spine, the psoas minor appears as a slender fusiform belly that quickly becomes a long flat tendon descending on the anteromedial surface of psoas major. Inferiorly, that tendon fans onto the pelvic brim, blending with the iliopubic eminence and pecten pubis region and often sending fibers into the iliac fascia overlying iliacus. Psoas major occupies the lateral side, with iliacus filling the iliac fossa and joining psoas major to form the iliopsoas tendon as it courses toward the lesser trochanter of the femur. A subtle muscle. Because psoas minor is absent in a large fraction of adults, a clear rendering of its morphology helps learners avoid mistaking it for a split psoas major tendon or an anomalous fascial band on cross sectional imaging. The flattened insertion on the pelvic brim is the teaching point, it relates to tensioning of the iliac fascia and can be implicated in iliopsoas compartment pain patterns that mimic hip joint pathology. This view also clarifies the close relationship of iliopsoas to the anterior hip capsule, a region targeted during anterior approaches to the hip and during image guided iliopsoas bursal injections for snapping hip syndrome. Ideal for gross anatomy and kinesiology teaching when discussing trunk flexors and hip flexion mechanics, and for radiology or sports medicine materials that compare normal variants of the iliopsoas region on MRI and CT. Surgical anatomy atlases covering the anterior pelvis and hip will also benefit from the clear depiction of the pelvic brim insertion and adjacent bony landmarks. Anatomical accuracy verified by SciePro's Medical Advisory Board.