1.5 cun lateral to the lower border of the spinous process of the 3rd lumber vertebra (L3).
How to locate
First identify the Tuffier's line which connects the highest points of the iliac crest. The spinous process of the 4th lumber vertebra (L4) mostly falls on this line.
Then identify the spinous process of the 3rd lumber vertebra (L3) by counting one up. Locate Qihai BL-24 1.5 cun lateral to the lower border of L3. Xiajishu Ex-B-5 is at the same level but 3 cun lateral to the lower border of L3.
Points located between Fufen BL-41 and Zhibian BL-54 are in the lateral branch of the Bladder Channel, while these between Fengmen BL-12 and Baihuanshu BL-30 are in the medial branch. Ex-B-5 does not belong to the Bladder Channel, but it is located at the place the lateral branch passes.