Which San Jiao point lies 2 cun proximal to SJ-4, in the depression between the radius and the ulna, on the radial side of the extensor digitorum communis tendons?

• A. SJ-4
• B. SJ-5
• C. SJ-6
• D. SJ-7

Answer: (B)

Waiguan sits along the San Jiao channel two cun proximal to the wrist point Yangchi. It is located in the depression between the radius and ulna, on the radial (thumb) side of the extensor digitorum communis tendon. This exact placement matches the description in the question, so it’s the correct choice. The wrist point is at the crease between the radius and ulna, not two cun up the forearm, and the other points lie at different distances or positions along the channel, so they don’t fit this description.