SJ-04 (Yang Chi) Yang Pool

What does SJ-04 Yang Chi do?

Yang Chi SJ-04 is the Yuan (Source) point of the San Jiao channel of Hand Shao Yang — the point at which the original qi of that channel is said to surface and collect — and its recorded work is to relax the sinews and alleviate pain, and to clear heat. Sacred Lotus sources & references record that classification and those actions directly. The classification carries more weight on this channel than on most, because of what the classical texts say the San Jiao is: the Nan Jing treats the San Jiao as the pathway through which the original (yuan) qi of the whole body moves, which makes its Source point the place where that idea comes to a single location on the wrist.

• Relaxes the sinews and alleviates pain — the first recorded action and the busiest one in modern practice. SJ-04 sits in a hollow on the back of the wrist joint itself, and it is the San Jiao channel's local point for pain, stiffness, weakness and swelling of the wrist, hand and forearm, and for pain referred along the channel to the elbow and shoulder.
• Clears heat — the second recorded action, and the one that reaches beyond the wrist. It underlies the classical indications of febrile disease, malarial disorders and the dry mouth and thirst recorded in our own indication list.
• Regulates the San Jiao and its original qi — the Source-point action proper. A Source point is used where the diagnosis is the channel or its organ rather than a precise pattern, because it regulates rather than only tonifying or only draining. On this channel the classical claim goes further than usual: the San Jiao is described as the "special fu" that distributes original qi, so its Source point is treated as a general regulating point rather than merely a local one.
• Benefits the ears and the side of the head — the channel action. The San Jiao channel's described course runs from the ring finger up the back of the arm, over the shoulder, around the ear and to the outer end of the eyebrow, which is why a wrist point carries deafness and tinnitus among its recorded indications.
• Serves as a diagnostic point — like all Source points, tenderness or a change in the hollow at SJ-04 is read as referring to its own channel. Modern work has taken that idea literally enough to measure it, and the measurement studies are described under research below.

Source: Sacred Lotus sources & references (channel, Yuan Source classification and existing action record); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 395); Chinese Acupuncture & Moxibustion (p. 203); Source-point scheme per Ling Shu (Spiritual Pivot), Chapter 1; Nan Jing (Classic of Difficulties), on the San Jiao and the original qi; cross-referenced against multiple online sources.

What is SJ-04 Yang Chi used for?

Yang Chi SJ-04 is used above all for the wrist — pain, stiffness, weakness and swelling of the wrist and hand are its everyday indications — and after that for pain along the arm and shoulder, for the ears, and for the classical presentations of thirst and febrile disease. The indications carried in Sacred Lotus sources & references are pain in the arm, shoulder and wrist, malaria, deafness and thirst; the standard reference literature sets them out more fully below. They describe traditional use, not proven treatment. This is a low-hazard point, and the reference facts are set out under needling.

• Pain, stiffness and swelling of the wrist
• Weakness of the wrist and inability to grip or lift
• Pain along the back of the forearm
• Pain in the elbow, upper arm and shoulder
• Numbness and weakness of the hand and fingers
• Deafness and tinnitus
• Sore throat and dryness of the mouth
• Excessive thirst — the classical "wasting and thirsting" presentation
• Febrile disease with no sweating
• Malarial disorders with alternating chills and fever
• Aching and heaviness of the shoulder and neck along the channel
• Redness and pain of the eyes
• Cold hands and poor circulation to the fingers

Source: Sacred Lotus sources & references (existing indication record); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 395); Chinese Acupuncture & Moxibustion (p. 203).

Where is SJ-04 Yang Chi, and how is it used in practice?

Yang Chi lies in a hollow on the back of the wrist, on the crease of the wrist joint itself, just to the little-finger side of the tendons that run to the fingers. Sacred Lotus sources & references give it as the depression on the transverse crease of the dorsum of the wrist lateral to the tendon of extensor digitorum communis; Deadman & Al-Khafaji fix the same hollow as lying between the tendons of extensor digitorum communis and extensor digiti minimi. The practical finding method is the same either way: extend the wrist, and the hollow appears between the taut tendons on the back of the joint.

In practice SJ-04 is used in two registers. Locally it is the San Jiao channel's wrist point, chosen for wrist pain, stiffness, swelling and weakness, and it is one of the three "yang" wrist points that are routinely needled as a group. As the channel's Source point it is chosen where the treatment is aimed at the San Jiao itself or at the channel's whole course, and it is the point palpated when the San Jiao is being assessed. It is a comfortable, accessible point with the carpal bones close behind it, and moxibustion is recorded as applicable and is much used where the wrist is cold and painful.

Which points is SJ-04 combined with?

• With Yang Xi LI-05 and Yang Gu SI-05 — the "three yang points of the wrist", one on each of the three yang channels of the hand, encircling the back of the joint. This is the standard local treatment for the wrist and it is not merely a textbook convention: a literature analysis of 120 acupuncture prescriptions and 143 points used for rheumatoid arthritis found that, for the wrist joint specifically, the highest-frequency point pair was Yangxi LI-05 with Yangchi TE-04, at 28 occurrences (Zhongguo Zhen Jiu 2017;37(2):221–224, PMID 29231492). That is a point-specific finding about this exact pairing.
• With Wai Guan SJ-05 — two cun proximal on the same channel, the Connecting point and the Confluent point of the Yang Linking Vessel, and the busiest point on the San Jiao channel. SJ-04 and SJ-05 are needled together so routinely for the wrist and forearm that they function almost as a unit, and our SJ-05 record is defined partly in relation to this point.
• With Nei Guan P-06 — directly opposite on the palmar side of the wrist. Needling the front and back of the wrist together is the classic "through" arrangement for the joint, and P-06 brings the Pericardium channel's reach into the chest with it.
• With Da Ling P-07 — the Yuan-Luo pairing, and the most theoretically important combination SJ-04 has. The rule joins a channel's Source point to the Connecting point of its interior-exterior partner: the San Jiao's Source point on the back of the wrist with the Pericardium's Connecting point, Nei Guan P-06, on the front. Sacred Lotus sources & references confirm P-06 as the Pericardium's Luo point and P-07 Da Ling as its Yuan-Source point — and note that our library codes this channel P-06/P-07/P-08, not with the "PC" prefix used elsewhere.
• With San Jiao Shu BL-22 — the Shu-Yuan pairing, joining the Source point to its own organ's Back-Shu point on the lower back. Held here, and the other structured combination the Source classification makes available.
• With Zhong Zhu SJ-03 and He Gu LI-04 — added for pain and stiffness of the fingers and the back of the hand.
• With Qu Chi LI-11 and Jian Yu LI-15 — the "chain along the arm" arrangement used where pain runs from the wrist to the shoulder.

Where does SJ-04 sit among the Source points?

Sacred Lotus sources & references hold the full set of twelve Yuan Source points — LU-09 Tai Yuan, LI-04 He Gu, ST-42 Chong Yang, SP-03 Tai Bai, HT-07 Shen Men, SI-04 Wan Gu, BL-64 Jing Gu, KI-03 Tai Xi, P-07 Da Ling, SJ-04 Yang Chi, GB-40 Qiu Xu and LIV-03 Tai Chong. Every one of them lies at or just beyond the wrist or the ankle, and on the yin channels the Source point doubles as the Earth and Shu-Stream point, while on the yang channels — SJ-04 among them — it is a separate point in its own right. That distinction is worth holding: on a yang channel the Source point is an addition to the five-shu series, not one of its members.

Within its own channel, the San Jiao's five transporting points held here run SJ-01 Guan Chong (Jing-Well, Metal) at the ring finger, SJ-02 Ye Men (Ying-Spring, Water), SJ-03 Zhong Zhu (Shu-Stream, Wood), SJ-06 Zhi Gou (Jing-River, Fire) on the forearm and SJ-10 Tian Jing (He-Sea, Earth) at the elbow — with SJ-04 Yang Chi sitting outside that series as the Source point, SJ-05 Wai Guan as the Connecting point and SJ-07 Hui Zong as the Cleft point. SJ-04 lies between SJ-03 and SJ-05 on the wrist, which makes it the easiest place on the arm to see the yang-channel rule in the flesh: two points a fingerbreadth apart, one the Shu-Stream and Wood point, the other the Source point with no element at all.

Source: Sacred Lotus sources & references (both location records, Yuan Source classification, the full twelve-point Source set and the complete San Jiao five-shu series queried directly, alongside the SJ-03, SJ-05, SJ-06, SJ-07, SJ-10, P-06, P-07, BL-22, LI-04, LI-05, LI-11, LI-15 and SI-05 records — reproduced identically to the Source set carried in the GB-40 and BL-64 records); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 395); Chinese Acupuncture & Moxibustion (p. 203); PMID 29231492; cross-referenced against multiple online sources.

Where is SJ-04 located?

• A Manual of Acupuncture (p. 395): On the dorsum of the wrist, at the level of the wrist joint, in the depression between the tendons of extensor digitorum communis and extensor digiti minimi.
• Chinese Acupuncture and Moxibustion (p. 203): On the transverse crease of the dorsum of wrist, in the depression lateral to the tendon of m. extensor digitorum communis.

How is SJ-04 Yang Chi needled?

Stated plainly: SJ-04 is a low-hazard point. It lies in a hollow on the back of the wrist joint with the carpal bones close behind it, there is no body cavity, no organ and no great vessel in the needle path, and the depth our records carry — perpendicular 0.3 to 0.5 inch — is an ordinary shallow joint depth rather than a bounded safety figure. The structures worth naming are the extensor tendons the point is defined between, and they are landmarks rather than hazards. Everything below is recorded as neutral reference data describing what the textbooks and the published anatomical literature state. It is not instruction, and this page does not teach technique. Needling is carried out only by a qualified, licensed practitioner.

The angle and depth the texts record

• Sacred Lotus sources & references record perpendicular insertion of 0.3 to 0.5 inch, with moxibustion applicable. That is a shallow figure appropriate to a point directly over a joint line, and it is not accompanied by any caution in our record — which is itself the informative fact, given how many points in this library are.
• Deadman & Al-Khafaji (p. 395) and Chinese Acupuncture & Moxibustion (p. 203) record a comparable shallow perpendicular range. Neither attaches a hazard caution of the kind both attach to the thoracic, abdominal, orbital and occipital points.
• The wrist is extended to locate the point. Both our location records define SJ-04 by the tendons on the back of the wrist, and those tendons only stand out when the wrist is extended and the fingers are moved — which is the practical reason the joint is positioned before the point is found rather than after.
• Moxibustion is recorded as applicable and is commonly used, particularly where the wrist is cold, stiff or painful from cold and damp.

What actually lies beneath — the anatomy of the back of the wrist

• Tendons, not vessels. The point sits in the hollow between the extensor tendon groups on the dorsum of the wrist, immediately over the extensor retinaculum and the wrist joint capsule, with the carpal bones behind. The named landmarks in both our location records — extensor digitorum communis and extensor digiti minimi — are tendons, and the classical description of the point as a "pool" is a description of the hollow they leave between them.
• The radial artery is on the other side. The wrist's two prominent arteries lie on the palmar aspect and at the anatomical snuffbox on the thumb side; neither is under this hollow. The dorsal venous network of the hand crosses this region superficially, which is why a small bruise is the commonest event here, as it is at most hand and wrist points.
• The nerve supply is cutaneous. The dorsal branch of the ulnar nerve and the superficial branch of the radial nerve supply the skin of this region. A brief radiating sensation toward the fingers is sometimes reported and is a cutaneous-nerve response, not an injury.
• A dissection study describes the needle path at this point — in rabbits. A comparative anatomical study located the San Jiao channel's five-shu points and its Source point in ten New Zealand rabbits by reference to the WHO standard and the Chinese national standard for human point locations, then dissected each and recorded what a needle passes through, including at Yangchi. The study recorded that the channel's forelimb points are supplied superficially by cutaneous branches of the ulnar and radial nerves and the medial brachial cutaneous nerve, and in the deep layer by branches of the ulnar and radial nerves (Zhen Ci Yan Jiu 2020;45(7):557–563, PMID 32705830). This was a rabbit study, and rabbit forelimb anatomy is not the human wrist; it is cited for the layered description it gives, not as a human measurement, and no depth figure from it is applied to a person.
• No imaging study measuring a safe needling depth at SJ-04 could be located, and none is needed in the way it is at the thoracic, abdominal and cranial points: the carpus lies behind the point and there is no cavity to enter. Two systematic reviews of the safe-depth literature — 33 studies in the first, 47 in the second — concluded in any case that measured depths for the same point differ greatly between subject groups and methods, and that "safe depth" has never been standardised (J Altern Complement Med 2011;17(3):199–206, PMID 21417806; Evid Based Complement Alternat Med 2013;2013:740508, PMID 23935678).

What the case literature documents at points of this kind

• The ordinary events are minor. Bruising and brief local soreness are what the reference literature records at hand and wrist points. A meta-analysis of prospective clinical studies found that about half of all recorded acupuncture adverse events across the whole repertoire were bleeding, pain or flare at the needle site (Bäumler P et al., BMJ Open 2021;11:e045961, PMID 34489268).
• Honest limit. We could not source any published case report of injury at SJ-04, and none is asserted. Where a point is low-hazard, the useful thing is to say so plainly rather than to import a warning from elsewhere, and that is what is done here.

Risk in proportion

The same meta-analysis estimated serious adverse events in acupuncture at approximately 1 per 10,000 patients and around 8 per million treatments, placing it among the safer treatments in medicine (PMID 34489268). Systematic reviews of the Chinese case literature reach the same conclusion about where the events cluster: they concentrate at points over the chest, the abdomen, the neck and the orbit, and are attributed chiefly to improper technique (He W et al., J Altern Complement Med 2012;18(10):892–901, PMID 22967282; Zhang J et al., Bull World Health Organ 2010;88(12):915–921C, PMID 21124716, PMC2995190). SJ-04 is not in that group, and the accurate summary is that it is one of the straightforward points of the repertoire.

Source: Sacred Lotus sources & references (existing needling and location records); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 395, surface and deep anatomy of the dorsum of the wrist); Chinese Acupuncture & Moxibustion (p. 203); PMID 32705830 (rabbit comparative anatomy); PMID 21417806; PMID 23935678; PMID 34489268; PMID 22967282; PMID 21124716 (PMC2995190) — each verified resolvable and checked for retraction status before citation.

What does the name Yang Chi mean?

Yang Chi means "Yang Pool" — yang, the yang aspect, and chi, a pool or pond. Sacred Lotus sources & references translate it exactly that way, and the name is a plain description of what the hand does. The back of the wrist is its yang surface, and the hollow between the extensor tendons on that surface fills like a small pool when the wrist is extended. The yang also names the channel: the San Jiao Channel of Hand Shao Yang. The name therefore says which surface, which channel and what the point feels like under the finger, all in two characters.

The wrist carries three such "yang" names side by side, one on each yang channel of the hand, and reading them together is the quickest way to fix the region: Yang Xi LI-05, "Yang Ravine", on the thumb side; Yang Chi SJ-04, "Yang Pool", in the middle; and Yang Gu SI-05, "Yang Valley", on the little-finger side. All three are held in Sacred Lotus sources & references, and the three water-landscape words — ravine, pool, valley — describe three hollows across the back of one joint.

Why does the Yuan (Source) classification matter at SJ-04?

The Source points are set out in the first chapter of the Ling Shu, where they are described as the places at which the original (yuan) qi of each channel lingers and collects. Three practical consequences follow. First, a Source point can be used in either excess or deficiency — it regulates rather than only tonifying or only draining, which makes it a safe general choice when the diagnosis is a channel or an organ rather than a precise pattern. Second, Source points are diagnostic: they are palpated for tenderness, slackness or change, and the finding refers to their own channel. Third, they anchor two structured combinations — the Yuan-Luo pairing, joining a channel's Source point to the Connecting point of its partner channel (here SJ-04 with Nei Guan P-06), and the Shu-Yuan pairing, joining the Source point to the organ's Back-Shu point (here San Jiao Shu BL-22). Knowing SJ-04 is the Source point is what makes those combinations available.

On this channel there is an additional layer. The Nan Jing describes the San Jiao as the pathway through which the body's original qi is distributed — the "special fu" with a name but no form. A channel whose classical role is to carry original qi has a Source point that is, in the tradition's own terms, unusually well named: Yang Chi is where the yuan qi of the yuan-qi channel gathers. Whatever one makes of that reasoning, it is the reason SJ-04 is treated in the classical literature as a general regulating point rather than only a wrist point.

Why is the Source point separate from the Shu-Stream point on the San Jiao channel?

Because the San Jiao is a yang channel, and this is the rule that separates yang channels from yin ones. On the six yin channels the Source point and the Shu-Stream point are the same point: LU-09 Tai Yuan, SP-03 Tai Bai, HT-07 Shen Men, KI-03 Tai Xi, P-07 Da Ling and LIV-03 Tai Chong are each simultaneously the channel's Source point and its Shu-Stream and Earth point — a fact confirmed directly by our own records, every one of which carries both classifications. On the six yang channels the two come apart: the Source point is an additional, separate point lying just proximal to the Shu-Stream point, and it carries no five-shu classification and no element of its own. SJ-04 Yang Chi is the San Jiao channel's Source point and carries no element; SJ-03 Zhong Zhu, a short distance distal on the back of the hand, is the channel's Shu-Stream and Wood point. Two points, two roles, a fingerbreadth apart — the same relationship our BL-64 record describes between BL-64 Jing Gu and BL-65 Shu Gu on the side of the foot.

The classical explanation is that the yang channels, being more exterior and carrying more qi, require a dedicated resting place for the original qi that the yin channels can accommodate within the five-shu series itself. The practical consequence is concrete: on a yin channel, choosing the Source point and choosing the Shu-Stream point are the same act; on a yang channel they are two different choices.

Is SJ-04 or SJ-10 the Source point of the San Jiao channel?

Discrepancy, flagged rather than silently reconciled. SJ-04 Yang Chi is the Yuan-Source point of the San Jiao channel; SJ-10 Tian Jing is the He-Sea and Earth point. That is what Sacred Lotus sources & references hold, and it is what the standard reference literature holds. The abstract of a published rabbit anatomical study of this channel (Zhen Ci Yan Jiu 2020;45(7):557–563, PMID 32705830) describes TE-10 as the "Source-point" of the San Jiao meridian and lists Yangchi TE-04 among the five-shu points it examined — precisely the reverse of both classifications. Our SJ-10 Tian Jing record flags the same conflict from its own side, and this record closes it from this one. Our classification is retained on both pages. A reader meeting that wording elsewhere should treat it as a labelling error in that paper rather than as a competing tradition.

Is there research on SJ-04 Yang Chi?

SJ-04 has no trial of its own, but it has something less common: it is one of the twelve points that the measurement literature on Source points keeps returning to, and it appears with a named partner in a point-selection analysis for the wrist. The honest summary is that the point-specific research is measurement research and point-selection research, not efficacy research.

• Source points as diagnostic points, measured. A study measured the cutaneous electrical resistance of all twelve Yuan Source points bilaterally in 116 patients with intracranial tumours before and one week after surgery, against 60 healthy controls. Resistance was significantly lower at the Source points in patients than in controls. Among the points whose values changed significantly after surgery on both sides were BL-64, LU-09, P-07, SP-03, LIV-03, KI-03, GB-40 and ST-42 (Zhen Ci Yan Jiu 2010;35(1):52–55, PMID 20458908). SJ-04 was among the twelve points measured but was not among those reported as changing significantly on both sides — a distinction worth stating precisely rather than glossing, and one our BL-64 record makes from the other direction. It is an observational measurement study, not a test of treatment.
• The wrist pair, from a point-selection analysis. A literature analysis of acupuncture for rheumatoid arthritis assembled 120 prescriptions using 143 points from six Chinese and English databases and analysed point selection by body region. For the wrist joint, the highest-frequency combination was Yangxi LI-05 with Yangchi TE-04 (frequency 28) — the local pair described under practice above (Zhongguo Zhen Jiu 2017;37(2):221–224, PMID 29231492). This measures what practitioners and trialists chose, not whether it worked, but it is a genuinely point-specific finding about this exact combination.
• Whole-body electrical mapping in jaw disorder. A clinical study measured qi at 24 representative points of the twelve channels by the Ryodoraku method in 40 adults with temporomandibular dysfunction; Yangchi TE-04 was the representative point used for the San Jiao channel. Total measured values were below the reference range, and the energetic planes with the greatest imbalance were Shao Yang — the San Jiao and Gall Bladder pair — and Shao Yin (Rasera Zotelli VL et al., J Acupunct Meridian Stud 2018;11(1):1–6, PMID 29482796). Forty volunteers, no control group and a measurement method whose validity is itself debated; it is recorded because it is one of the few studies in which this point is the named object of measurement.
• Modern protocols in which the point appears. SJ-04 is a standard component of wrist and hand prescriptions. An electroacupuncture study in 30 patients with carpal tunnel syndrome used Qu Chi LI-11, Yangchi TE-04, Shou San Li LI-10, Nei Guan P-06 and He Gu LI-04, reporting improved median nerve conduction velocity and reduced proximal nerve swelling (Zhongguo Zhen Jiu 2013;33(8):700–702, PMID 24195210). A randomised controlled trial protocol for 222 patients recovering from distal radius fracture selects Yang Xi LI-05, Yang Chi TE-04, Yang Gu SI-05, He Gu LI-04 and Tai Yuan LU-09 for the electroacupuncture arm (J Orthop Surg Res 2022;17(1):517, PMID 36456969, PMC9713955) — note that this is a published protocol, not results. A metabolomics study of acupuncture in 30 patients with rheumatoid arthritis included Yangchi TE-04 among nine bilateral points (Zhen Ci Yan Jiu 2021;46(2):145–151, PMID 33788436). In every case the point is one of several and the result belongs to the protocol.

What is missing should be said plainly: there is no randomised trial of SJ-04 alone, no sham-controlled study of it, and no clinical study in which it is the point under test. Rather than cite whole-protocol trials as though they concerned this point, the accurate statement is that SJ-04's standing rests on its classification as the Source point of the San Jiao channel and on long clinical use.

How does SJ-04 compare with the points around it?

Zhong Zhu SJ-03 lies just distal on the back of the hand and is the Shu-Stream and Wood point — the San Jiao channel's tonification point, and a different classification entirely from this one, which is the clearest illustration on the arm of the yang-channel Source rule. Wai Guan SJ-05 lies two cun proximal and is the channel's Connecting point and the Confluent point of the Yang Linking Vessel; it is the busier point of the two and the one reached for in exterior conditions, one-sided headache and the ear. Zhi Gou SJ-06 further up the forearm is the Jing-River and Fire point and the horary point. Hui Zong SJ-07 is the Cleft point. Tian Jing SJ-10 at the elbow is the He-Sea and Earth point and the channel's sedation point — and the point most often mislabelled as the Source point, as set out above. Across the wrist, Da Ling P-07 is the Source point of the paired Pericardium channel and Nei Guan P-06 its Connecting point, SJ-04's Yuan-Luo partner. Along the joint, Yang Xi LI-05 and Yang Gu SI-05 complete the three yang wrist points. All are held in Sacred Lotus sources & references.

Source: Sacred Lotus sources & references (name, translation, channel, Yuan Source classification, the full twelve-point Source set and the complete San Jiao five-shu series queried directly, alongside the SJ-03, SJ-05, SJ-06, SJ-07, SJ-10, P-06, P-07, BL-22, BL-64, GB-40, LI-04, LI-05, LI-11, LI-15 and SI-05 records); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 395); Chinese Acupuncture & Moxibustion (p. 203); Ling Shu (Spiritual Pivot), Chapter 1, on the Source points; Nan Jing (Classic of Difficulties), on the San Jiao and the original qi; PMID 20458908; PMID 29231492; PMID 29482796; PMID 24195210; PMID 36456969 (PMC9713955); PMID 33788436; PMID 32705830 — each verified resolvable and checked for retraction status before citation; cross-referenced against multiple online sources.