Which muscle arises from the lumbar spine and descends into the false pelvis and lies posterior to the inguinal canal?

• A. Psoas major
• B. Iliopsoas
• C. Piriformis
• D. Obturator internus

Answer: (A)

The psoas major fits this description. It originates from the lumbar spine (the bodies and transverse processes of L1–L5) and descends through the retroperitoneal space into the pelvic region, where it lies adjacent to the inguinal canal and remains posterior to it as it moves toward the thigh (where it joins with iliacus to form the iliopsoas). This lumbar origin, descent into the pelvic area, and posterior position relative to the inguinal canal are characteristic of the psoas major. The other muscles have different origins and paths: the piriformis comes from the anterior sacrum and passes through the greater sciatic foramen; the obturator internus arises from the obturator membrane; neither matches the described course.