LI-02 (Er Jian) Second Space

What does LI-02 Er Jian do?

LI-02 is the Ying-Spring and Water point of the Large Intestine channel — and because the Large Intestine is a yang Metal channel, Water is Metal’s child, which makes LI-02 the channel’s SEDATION point. That is the classification that matters most about it: when the classical texts call for draining heat or excess from this channel, LI-02 is the point the five-shu system nominates.

• Expels wind, clears heat and reduces swelling — the Ying-Spring function; Ying-Spring points across all twelve channels are the classical heat-clearing members of the five-shu set
• Alleviates pain — applied along the channel’s course to the face, teeth and throat

The full five-shu picture, derived from this site’s own element records rather than from a summary: LI-01 Shang Yang is Metal, LI-02 is Water, LI-03 San Jian is Wood, LI-05 Yang Xi is Fire, LI-11 Qu Chi is Earth. Large Intestine is yang Metal, so:

• Tonification (mother) point — LI-11 Qu Chi (Earth, the mother of Metal)
• Sedation (child) point — LI-02 Er Jian (Water, the child of Metal) — this point
• Horary point — LI-01 Shang Yang (Metal on a Metal channel)
• Controlling-element point — LI-03 San Jian (Wood, which Metal controls) — none of the three roles

Note also that on yang channels the Yuan-Source point is separate from the Shu-Stream: LI-04 He Gu holds the Yuan classification here, not LI-03. On yin channels the two coincide.

Source: Sacred Lotus sources & references (channel, element and action records; the full Large Intestine five-shu series and LI-04's Yuan classification queried from our own data), cross-referenced against multiple online sources.

What is LI-02 Er Jian used for?

LI-02 is used for heat signs at the far end of its channel — the eyes, nose, mouth and throat — and for febrile conditions. Our own indication record is reproduced here in full.

• Blurring of vision
• Nosebleed (epistaxis)
• Toothache
• Sore throat
• Febrile disease

Why a point on the index finger reaches the face. The Large Intestine channel runs from the index finger up the arm and neck to terminate beside the nose, passing through the lower teeth and jaw. Distal points are classically used for the far end of their own channel, and the Yang Ming channels are the pair associated with the face and mouth — the same logic that makes LI-04 He Gu one of the Four Commands for the face and mouth.

How it differs from its neighbours. LI-01 Shang Yang is the Jing-Well point at the nail corner, classically bled for acute sore throat and collapse. LI-03 San Jian, immediately proximal, shares the throat and tooth indications but is the controlling-element point rather than the sedation point. LI-04 He Gu is the Yuan-Source point and by far the most used of the group. LI-11 Qu Chi at the elbow is the channel’s principal heat-clearing point and its tonification point. All are held here.

Source: Sacred Lotus sources & references (indication record; neighbouring-point classifications queried from our own data), cross-referenced against multiple online sources.

Where is LI-02 Er Jian located?

LI-02 lies on the thumb side of the index finger, in the depression just beyond the big knuckle — distal to the metacarpophalangeal joint. With the finger slightly bent the hollow is easy to feel, which makes this one of the more reliably palpable points on the hand.

• Distal to the knuckle joint, on the radial (thumb) side of the index finger
• Distal to LI-03 San Jian, which sits proximal to the same joint — the two are on opposite sides of it
• Proximal to LI-01 Shang Yang at the corner of the fingernail

On the name. “Er Jian” means Second Space — it is simply the second point on the channel, counted from LI-01. Its neighbour LI-03 is “San Jian”, Third Space, by the same counting. These names are positional and carry no clinical information, which is worth knowing so that no meaning is read into them.

Source: Sacred Lotus sources & references (location record, retained unchanged), cross-referenced against multiple online sources.

• A Manual of Acupuncture (p. 101): On the radial border of the index finger, in a depression just distal to the metacarpo-phalangeal joint.
• Chinese Acupuncture and Moxibustion (p. 139): In the depression of the radial side of the index finger, distal to the 2nd metacarpal-phalangeal joint. The point is located with the finger slightly flexed.

How is LI-02 Er Jian needled?

The standard texts record perpendicular insertion to roughly 0.2–0.3 inch, with moxibustion applicable. What follows is a neutral record of what the reference literature documents, not instruction for a reader.

• Angle and depth as recorded: perpendicular, 0.2–0.3 inch — shallower than LI-03’s recorded 0.5–0.8 inch, because there is little soft tissue over the finger’s phalanx.
• Moxibustion: recorded as applicable.
• Regional anatomy: the dorsal digital branches of the radial nerve and the digital vessels run along the finger’s margins, superficial and lateral to the point; the phalanx lies immediately beneath.

Hazard, stated proportionately. This is a low-hazard point: no body cavity, no major vessel and no large nerve trunk lies in the recorded needle path, and the depth is very shallow. Saying so plainly is more useful than attaching a generic caution — the points in this library that carry real hazards are documented with measured anatomy, and this is not one of them. No case report naming LI-02 as the site of an injury was located, and none is asserted. No study measuring a safe depth at LI-02 could be located, and none is borrowed from a neighbour.

Source: Sacred Lotus sources & references (needling record, retained unchanged), cross-referenced against multiple online sources; regional anatomy from standard anatomical description.

Is there research on LI-02 Er Jian?

No trial isolates LI-02, and its standing rests on the classical record and on the five-shu system rather than on modern evidence. Where it appears in the literature it is one ingredient in a multi-point protocol, most often for facial or dental complaints, and a study that includes a point in a protocol is not evidence about that point.

Why that is unsurprising. Modern attention on this channel has gone almost entirely to LI-04 He Gu, which is among the most-studied points in the world, and to LI-11 Qu Chi. Both are held here and both carry their own research sections. Evidence about a combination that includes LI-02 is not evidence about LI-02.

A note on searching for it. Point-code searches are unreliable for the minor points on this channel. A search for its neighbour LI-03 returned twenty-eight records, of which none concerned that point — one was about LI-4 entirely, returned by the code match. Any claim attached to LI-02 should be checked against what a study actually measured, not against a hit count.

What a reader can rely on. LI-02’s classification is firm and checkable: it is the Ying-Spring and Water point, and therefore the sedation point, of a yang Metal channel. That places it precisely within a system that has been consistent across the fourteen channels derived from first principles in this library.

Source: Sacred Lotus sources & references (classification and indication records); PubMed searched and results read individually rather than counted; no unverifiable or retracted source is cited.