Which edge of the quadratus lumborum is most accessible?

• A. Lateral
• B. Medial
• C. Superior
• D. Inferior

Answer: (A)

The edge closest to the surface is the lateral border, and that makes it the most accessible. The quadratus lumborum sits in the posterior abdominal wall, and its lateral edge forms the outer margin of the muscle along the flank. That part sits relatively superficially, with less overlying depth and fewer obstructing structures, so it’s easier to palpate or access for work like manual therapy. The medial edge sits against the psoas major and vertebral column, the superior border is near the 12th rib and diaphragm, and the inferior border near the iliac crest is deeper and shielded by hip structures, making them harder to reach.