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

• A. BL 29
• B. BL 31
• C. BL 34
• D. BL 30

Answer: (D)

The Bladder channel has a group of points along the sacrum that sit about 1.5 cun lateral to the midline at the level of each posterior sacral foramen. The level described in the question is the fourth posterior sacral foramen, so the point located there is the Bladder point associated with that foramen, commonly identified as BL-30. This makes BL-30 the best match for a location described as 1.5 cun lateral to the midline at the fourth posterior sacral foramen. The other sacral-foramen levels correspond to different Bladder points, so they wouldn’t fit this exact location.