Which BL point is located 1.5 cun lateral to the midline at the level of the second posterior sacral foramen?

• A. BL 29
• B. BL 28
• C. BL 27
• D. BL 30

Answer: (B)

Back-shu points of the Bladder follow a horizontal line 1.5 cun lateral to the midline at the level of each posterior sacral foramen. The level of the second posterior sacral foramen corresponds to the Back Shu point for the Bladder, located 1.5 cun from the midline. That landmark identifies the point as BL 28.

To visualize, imagine the four posterior sacral foramina: the first corresponds to the previous Back Shu point, the second to the one in question, the third to the next, and the fourth to the last. So the described position—1.5 cun lateral to the midline at the level of the second posterior sacral foramen—maps to the Bladder Back Shu point BL 28. This is the point you’d use for bladder-related and lower-jiao issues.