LI3 Sanjian: At the index knuckle, find the hollow on its thumb-facing side towards the wrist, on the back of the hand. Landmark schematic; not to scale.

LI3 (Sanjian / Third Space) Acupuncture Point Guide

October 18, 2026

Practitioner Guide from The Acupuncture Supply Co.

LI3 Sanjian belongs to the Large Intestine channel. This Project Lotus guide focuses on reliable surface landmarks, nearby-point distinctions and safe professional assessment.

Quick reference

Point	LI3 — Sanjian
Channel	Large Intestine — Hand Yangming
Traditional classification	Shu-Stream; Wood
Region	Dorsoradial hand
Laterality	Bilateral

Location and landmark sequence

At the index knuckle, find the hollow on its thumb-facing side towards the wrist, on the back of the hand.

Support the limb so the illustrated surface is accessible. Confirm the thumb or little-finger side for hand and forearm points, or the inner or outer ankle for foot points.
Palpate the named joint, bone or tendon landmarks before estimating a position.
At the index knuckle, find the hollow on its thumb-facing side towards the wrist, on the back of the hand.
Check the relationship to nearby points and reassess on the individual patient.

Distinguishing nearby points

LI3 is proximal to the second MCP joint; LI2 is distal. Neither is the midshaft landmark of LI4.

Traditional context

Shu-Stream; Wood is the traditional classification used here. Classification helps organise channel theory; it is not evidence that an individual point treats a particular disease. Selection depends on a complete assessment and a coherent treatment principle.

Traditional functions and applications

Within traditional East Asian medicine, this point is described in terms of exterior wind and heat clearing.

Traditionally considered for hand-channel symptoms and selected throat, dental or facial presentations. These are historical treatment concepts, not proven disease-specific effects of this point alone. Select points from the full assessment rather than a symptom list.

Moxibustion

Moxa is not an automatic addition. Assess the treatment principle, skin condition and sensation; use appropriate training, supervision and burn prevention if heat is considered.

Anatomy and essential safety

Small digital vessels, sensory branches, tendons and joint structures are close together in the hand. Inspect skin, circulation and sensation, and account for arthritis, injury or surgery.

Inspect skin, circulation and sensation; avoid infected, ulcerated or otherwise unsuitable tissue.
Review relevant medication, bleeding risk, pregnancy, surgery and previous reactions.
Use sterile single-use needles, appropriate infection control and safe sharps disposal.
Choose depth, angle and stimulation through accredited training and patient-specific anatomical assessment.

When assessment takes priority

A hot swollen limb with fever, new weakness, persistent numbness, significant trauma or an infected wound needs medical assessment. Acute chest pain, collapse or severe breathlessness requires emergency care; a traditional channel association must never delay referral.