Which San Jiao point lies 3 cun proximal to SJ-4, in the depression between the radius and ulna, on the radial side of the extensor digitorum communis muscle?

• A. SJ-5
• B. SJ-6
• C. SJ-7
• D. SJ-8

Answer: (B)

Understanding how the San Jiao channel is marked on the forearm helps you pinpoint points by fixed distances from Houxi (SJ-4). The point located 3 cun proximal to Houxi sits between the radius and ulna, on the radial side of the extensor digitorum communis tendon. This location corresponds to Zhigou (SJ-6). Because the description matches this exact spot, it’s the correct choice. The other points in that region are at different distances from Houxi or lie in different anatomical relationships, so they don’t fit the description as precisely.