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

• A. SJ-7
• B. SJ-8
• C. SJ-9
• D. SJ-5

Answer: (B)

Locating this point uses a straight forearm line from the wrist point 4 cun up toward the elbow, placed between the radius and ulna on the radial side of the extensor digitorum communis. Four cun proximal to SJ-4 along the San Jiao channel that spot corresponds to San Jiao eight. This placement matches both the distance from SJ-4 and the anatomical landmarks, sitting on the dorsal forearm between the bones and just beside the extensor digitorum communis.