MusclePosterior abdominal wall
Quadratus lumborum
Latin: M. quadratus lumborum
Location: Abdomen
View the quadratus lumborum in 3DOrigin
Iliac crest and iliolumbar ligament.
Insertion
Twelfth rib and transverse processes of L1–L4.
Action
Side-bends and stabilises the lumbar spine; anchors the twelfth rib down in forced expiration.
Nerve supply
T12–L4 anterior rami.
Blood supply
Iliolumbar artery.
Clinical relevance
QL spasm follows acute lumbar disc strain — the deep ache beside the spine; the muscle is the plane for the retroperitoneal approach to the kidney.
Educational anatomy reference, not medical advice. About this content.