Which BL point lies over the third posterior sacral foramen?

• A. BL 33
• B. BL 32
• C. BL 34
• D. BL 31

Answer: (A)

The Bladder channel in the sacral region maps onto the posterior sacral foramina, with each point sitting directly over its corresponding foramen. The third posterior sacral foramen aligns with BL33, so BL33 sits over that foramen. The other sacral points align with the first, second, and fourth foramina (BL31, BL32, BL34), not the third. To locate it, identify the sacral foramina on the back and find BL33 0.5 cun lateral to the midline at the level of the third foramen.