BL22 is located 1.5 cun lateral to the lower border of the spinous process of which vertebra?

• A. L2
• B. L3
• C. L1
• D. L4

Answer: (C)

Back-shu points sit 1.5 cun lateral to the lower border of the spinous process at the vertebral level that corresponds to the organ. BL-22 is the back-shu point for the San Jiao, so its location is at the lower border of the spinous process of the first lumbar vertebra, with a horizontal 1.5 cun sweep to the side. To find it on a person, locate the L1 spinous process and mark 1.5 cun laterally. This vertebral level is what ties BL-22 to the San Jiao, making it the correct placement.