LI-3 Sanjian (三間) — Third Space

On the radial aspect of the index finger, proximal to the metacarpophalangeal joint, at the junction between the shaft and head of the second metacarpal bone.

With the fingers gently flexed, locate the point at the metacarpophalangeal joint of the index finger, at the transition between light and dark skin, posterior to the head of the second metacarpal.

First dorsal interosseous muscle. Innervated by the proper palmar digital nerve and the superficial branch of the radial nerve.

Perpendicular insertion, 0.5–2.0 cun (may be directed toward PC-8).

San (三), three, third; Jian (間), free space. This is the third point of the Large Intestine Meridian.