Which Back Shu point is located 1.5 cun lateral to L1?

The Back Shu point located 1.5 cun lateral to L1 is indeed BL-23, which corresponds to the Kidney.

To locate the Back Shu points, it's essential to know the anatomical landmarks. The first lumbar vertebra (L1) serves as a critical reference point for locating these points on the back. The point BL-23, being the Back Shu of the Kidney, specifically relates to the area around the lumbar spine and is located at the level of the L1 vertebra, 1.5 cun lateral from the midline.

In traditional Chinese medicine, each organ has a corresponding Back Shu point that is crucial for diagnostic and treatment purposes. The Kidney plays a vital role in many bodily functions, including the regulation of water, the storage of essence, and the health of the bones and marrow, which is why its Back Shu point is significant in acupuncture practice. Understanding these points and their anatomical relationships helps practitioners effectively target and treat various conditions.