Question: what is the function of the quadratus lumborum muscle?
Answer: Extension of lumbar vertebral column, with bilateral contraction (based on line of force passing ~3.5 cm posterior L3 rotation axis) Fixes the 12th rib during forced expiration. The quadratus lumborum assists the diaphragm in inhalation. Elevates the Ilium (bone), with ipsilateral contraction ("hip hiking")