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

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

Answer: (B)

The bladder channel has a set of points that sit at the level of the posterior sacral foramina, each one 1.5 cun lateral to the midline. The level described—the first posterior sacral foramen—corresponds to the point located there. That point is the one you’d use at the first foramen, which is why this matches the description. The next sacral foramina correspond to the subsequent bladder points (second foramen, third foramen, fourth foramen), which would be at the second, third, and fourth levels, not the first. To locate it on a patient, have them prone, identify the first posterior sacral foramen, then go 1.5 cun lateral to the midline to find the point.