GB-38 (Yang Fu) Yang Assistance

What does GB-38 Yang Fu do?

Yang Fu GB-38 is the Jing-River and Fire point of the Gall Bladder channel of Foot Shao Yang, on the outer lower leg four cun above the ankle bone, and its recorded work is to clear heat from the Gall Bladder channel, to harmonise Shao Yang, to benefit the sinews and bones, and to activate the channel and alleviate pain. Sacred Lotus sources & references record that classification and those four actions directly. Two things follow from the classification, and separating them is what makes the point intelligible. The Jing-River position is the fourth of the five transporting points, where the Ling Shu describes the channel's qi flowing freely like a river in its course. And because the Gall Bladder is a yang Wood channel, its Fire point is the child of the channel's own element — which makes GB-38 the channel's sedation point, the technical basis on which a point at the ankle is used to drain an overheated Gall Bladder.

• Clears heat from the Gall Bladder channel — the first recorded action, and the one that governs the point's leading indications: one-sided headache, pain at the outer corner of the eye, and heat along the side of the body. Fire draining Wood is the five-element reading of the same action, and it is set out in full under the notes below.
• Harmonises Shao Yang — the Gall Bladder and San Jiao form the Shao Yang pair, the "pivot" between exterior and interior in the six-channel scheme, and the presentation the tradition attributes to it is alternating chills and fever with fullness in the flanks. Our own indication record carries malarial disorders for this point, and this is the action behind it.
• Benefits the sinews and bones — an action GB-38 shares with its channel. The Gall Bladder channel carries the Hui-Meeting point of the sinews at GB-34 Yang Ling Quan and the Hui-Meeting point for marrow at GB-39 Xuan Zhong, both held here and both within a few cun of GB-38 on the same lower leg. GB-38 sits between them and takes a share of the same territory.
• Activates the channel and alleviates pain — the local and channel action. GB-38 is used for pain down the outer side of the leg, in the flanks and chest, in the armpit and in the lower back — the Gall Bladder channel's own course down the side of the body.
• Dissipates nodules — the action behind its recorded indication of scrofula, the chains of hard nodules in the neck and armpit that the tradition attributes to phlegm-fire congealing along the Shao Yang channels. GB-38 shares this indication with Tian Jing SJ-10 on the partner channel at the elbow, which our SJ-10 record carries from its own side.

One honest note on the classification. The Nan Jing assigns the Jing-River points a general indication for cough and wheezing with chills and fever, and for disorders of the voice. Sacred Lotus sources & references carry no respiratory or voice indication for GB-38, and none is added here; the classical scheme's general property and this particular point's documented uses do not coincide, which is normal and is worth stating rather than papering over.

Source: Sacred Lotus sources & references (channel, Jing-River & Fire classification and existing action record; the complete Gall Bladder five-shu series queried directly); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 455); Chinese Acupuncture & Moxibustion (pp. 219–220); Ling Shu (Spiritual Pivot), on the five-shu points; Nan Jing (Classic of Difficulties), on the five-shu indications and the mother-child rule; cross-referenced against multiple online sources.

What is GB-38 Yang Fu used for?

Yang Fu GB-38 is used above all for one-sided headache and for pain anywhere along the side of the body — the outer corner of the eye, the armpit, the flanks, the lower back and the outer leg — which is the Gall Bladder channel's own course from head to foot. The indications carried in Sacred Lotus sources & references are migraine, pain of the outer canthus, pain in the axillary region, scrofula, lumbar pain, pain in the chest, hypochondrium and lateral aspect of the lower extremities, and malarial disorders; 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.

• One-sided headache and migraine, particularly at the temple
• Pain at the outer corner of the eye
• Pain and swelling under the arm and in the armpit
• Pain in the flanks and hypochondrium — the region below the ribs at the side
• Pain and fullness in the chest
• Lower back pain, especially where it is worse on one side
• Pain, numbness and weakness down the outer side of the leg
• Pain and stiffness of the ankle
• Scrofula — chains of hard nodules in the neck and armpit
• Swollen and painful lymph nodes of the neck and armpit
• Malarial disorders with alternating chills and fever
• Aching of the whole body with no sweating
• Neck and shoulder stiffness along the side of the neck
• Bitter taste in the mouth and sighing, in Gall Bladder patterns

Source: Sacred Lotus sources & references (existing indication record); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 455); Chinese Acupuncture & Moxibustion (pp. 219–220).

Where is GB-38 Yang Fu, and how is it used in practice?

Yang Fu lies on the outer side of the lower leg, four cun above the tip of the ankle bone, at the front edge of the fibula. Sacred Lotus sources & references give it as slightly in front of the anterior border of the fibula, in the groove between extensor digitorum longus and peroneus brevis; Deadman & Al-Khafaji place it at the anterior border of the fibula at the same height. Both descriptions come to the same spot: run a finger up the front edge of the slender outer leg bone from the ankle, about a hand's breadth, and the point is in the soft groove just in front of it.

In practice GB-38 is a distal point used for problems a long way from itself. Its everyday use is one-sided headache and pain along the side of the body, and it is chosen in company with local points at the head or flank rather than for the leg. It is also — and this is worth knowing — one of the points most associated in the literature with warm needling, the technique in which a piece of moxa is burned on the needle handle; the only physical study we could find that names this point studies exactly that. Sacred Lotus sources & references record moxibustion as applicable here.

Which points is GB-38 combined with?

• With Xuan Zhong GB-39 — one cun below at three cun above the ankle bone, and the Hui-Meeting point for marrow. The two are immediate neighbours and the pair most easily confused; the distinguishing facts are the cun measurement and the classification, and both are held in Sacred Lotus sources & references.
• With Guang Ming GB-37 — one cun above at five cun, the Gall Bladder channel's Connecting point and its principal eye point. GB-37, GB-38 and GB-39 occupy three consecutive cun on the same leg with three entirely different classifications — Connecting point, Jing-River and Fire point, and Hui-Meeting point for marrow — which is one of the tidiest illustrations in the body of why the point categories exist.
• With Yang Ling Quan GB-34 — the He-Sea and Earth point below the knee and the Hui-Meeting point of the sinews, the channel's dominant point and its usual partner wherever the flanks, the sinews or the Gall Bladder itself are being treated.
• With Zu Lin Qi GB-41 and Wai Guan SJ-05 — the confluent pairing of the Girdling Vessel and the Yang Linking Vessel, the standard combination for one-sided headache and for pain along the side of the body. GB-38 is added to it as the channel's heat-draining point.
• With Tai Yang, Shuai Gu GB-08 and Feng Chi GB-20 — the local head points for one-sided headache, to which GB-38 is the distal Gall Bladder partner.
• With Tian Jing SJ-10 and Zhang Men LIV-13 — for scrofula and neck nodules. SJ-10 on the partner Shao Yang channel at the elbow is the tradition's principal distal point for dissolving nodules, and our SJ-10 record carries the same use from its own side.
• With Xing Jian LIV-02 — the Ying-Spring and Fire point of the paired Liver channel and its sedation point. Where a Wood pattern is being drained on both the yin and the yang side, LIV-02 and GB-38 are the two channels' child points and are the structural pair — a symmetry set out under the notes below.

Where does GB-38 sit among the five-shu points?

The five-shu points are the set of five on each channel between the toes and the knee, described in the Ling Shu as the stages of a river: the qi wells up, glides, pours, flows and finally enters inward. Sacred Lotus sources & references hold the complete Gall Bladder set, and it is worth seeing whole because the element assignments are what the mother-child rule works on:

• Jing-Well — Zu Qiao Yin GB-44, at the corner of the fourth toenail. Metal.
• Ying-Spring — Xia Xi GB-43, in the web between the fourth and fifth toes. Water — the mother of Wood, and therefore this channel's tonification point.
• Shu-Stream — Zu Lin Qi GB-41, on the top of the foot; also the Confluent point of the Girdling Vessel. Wood — Wood on a Wood channel, the horary or self point.
• Jing-River — Yang Fu GB-38, four cun above the outer ankle bone. Fire — the child of Wood, and therefore this channel's sedation point. This page.
• He-Sea — Yang Ling Quan GB-34, below the head of the fibula; also the Hui-Meeting point of the sinews. Earth — the element Wood controls.

The channel is completed by GB-40 Qiu Xu as the Yuan-Source point, GB-37 Guang Ming as the Connecting point and GB-36 Wai Qiu as the Cleft point, all held here. On yang channels the five-shu run Metal, Water, Wood, Fire, Earth from the extremity inward; on yin channels they run Wood, Fire, Earth, Metal, Water — which is why Ling Dao HT-04 and Jing Qu LU-08 on yin channels are Jing-River and Metal points while Yang Fu on this yang channel is Jing-River and Fire. Among the Jing-River points of the yang channels — a group that also includes Yang Xi LI-05, Jie Xi ST-41, Yang Gu SI-05, Kun Lun BL-60 and Zhi Gou SJ-06, all held here — GB-38 is the one whose channel is Wood, and that is what makes its position unique in the set.

Source: Sacred Lotus sources & references (both location records, Jing-River & Fire classification, and the complete Gall Bladder five-shu series with element assignments queried directly, alongside the GB-34, GB-36, GB-37, GB-39, GB-40, GB-41, GB-43, GB-44, SJ-05, SJ-06, SJ-10, LIV-02, LIV-13, LI-05, ST-41, SI-05, BL-60, HT-04 and LU-08 records); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 455); Chinese Acupuncture & Moxibustion (pp. 219–220); Ling Shu (Spiritual Pivot), on the five-shu points; cross-referenced against multiple online sources.

Where is GB-38 located?

• A Manual of Acupuncture (p. 455): On the lateral aspect of the lower leg, 4 cun superior to the prominence of the lateral malleolus, at the anterior border of the fibula.
• Chinese Acupuncture and Moxibustion (p. 219-220): 4 cun above the tip of the external malleolus, slightly anterior to the anterior border of the fibula, between m. extensor digitorum longus and m. peronaeus brevis.

How is GB-38 Yang Fu needled?

Stated plainly: GB-38 is a low-hazard point. It lies on the outer side of the lower leg with the fibula immediately behind it, there is no body cavity, no organ and no great vessel in the needle path, and the depth our records carry — perpendicular 0.5 to 0.7 inch — is an ordinary limb depth. The one structure worth naming is the common peroneal nerve, and the useful fact about it is a correction: that nerve winds around the neck of the fibula up near the knee, four to five cun above GB-38 and close to GB-34, not at this point. What runs beside GB-38 are the superficial peroneal nerve's branches in the muscle groove. Everything below is recorded as neutral reference data describing what the textbooks and the published 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 0.5 to 0.7 inch, with moxibustion applicable. That is a standard lower-leg depth 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. 455) and Chinese Acupuncture & Moxibustion (pp. 219–220) record a comparable perpendicular range. Neither attaches a hazard caution of the kind both attach to the thoracic, abdominal, orbital and occipital points.
• Moxibustion and warm needling. Moxibustion is recorded as applicable, and GB-38 is one of the points most associated in the physical literature with the warm needle — a piece of moxa burned on the handle of an inserted needle. What that technique actually does at this point has been modelled and measured, and the result is set out below.
• The point is located with reference to bone. Both our location records fix GB-38 against the anterior border of the fibula. That bony edge is the landmark and it is also, in practical terms, the backstop.

The measured anatomy, and the one study that names this point

• An ultrasound study that names GB38 among the points needing care. A validation study reviewed the insertion depth ranges recorded in the acupuncture literature for the five phase (five-shu) points, converted the traditional cun measures to centimetres by measuring limb landmarks in participants, marked the points on the skin to the World Health Organization specification, and then examined the anatomical structures within the stated insertion range using colour Doppler ultrasound. The authors divided the points into two groups: those whose recorded insertion depth ranges needed modifying, and those that required careful insertion. GB38 was placed in the second group, alongside LU-08, LU-09, LU-10, LI-05, ST-36, ST-41, SP-03, HT-04, HT-07, HT-08, SI-03, SI-08, BL-40, KI-02, KI-03, KI-10, KI-27, GB-34, LIV-03 and LIV-04 (Park M, Kim S, Complement Ther Med 2013;21(6):641–648, PMID 24280473). Two limits must be stated: it is described by its own authors as a pilot study, and no point-by-point figure is given in the abstract, so no millimetre depth for GB-38 is claimed here. What it establishes is that GB-38 was individually examined and was judged to have structures within its recorded range worth attending to — which is a more useful and more honest statement than either "no research exists" or a borrowed number.
• What lies beneath, in plain terms. The needle passes through skin and subcutaneous tissue into the groove between the long toe extensor and the short peroneal muscle, with the fibula immediately behind and the interosseous membrane deep to that. The superficial peroneal nerve descends in this compartment and its branches become subcutaneous in the lower leg, which is why a brief radiating sensation toward the foot is sometimes reported here. The anterior tibial vessels lie deeper and more medially, between the tibia and fibula.
• The nerve that is not here. The common peroneal nerve — the one that is genuinely superficial and vulnerable in the lower limb — winds around the neck of the fibula just below the knee, which is the region of Yang Ling Quan GB-34, not of GB-38. Stating this is useful because "peroneal nerve" is often attached to any lateral leg point; at four cun above the ankle the nerve has long since divided and its branches here are small and cutaneous.
• No imaging study measuring a safe needling depth in millimetres at GB-38 could be located, and none is quoted. None is needed in the way it is at the thoracic, abdominal and cranial points: the fibula 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 warm needle actually does at this point — measured

An engineering study built a numerical model of a warm (moxa-heated) needle in the calf section around the GB38 acupoint — needle, needle handle and surrounding tissue — and validated the model against measurements taken with a calibrated infrared camera. Along the centreline of the needle the temperature fell steeply from the burning moxa at about 200 °C to about 36 °C at the skin surface, and the tissue temperature immediately beside the needle was only about one degree higher than tissue elsewhere — roughly 36 °C against 35 °C. The authors' conclusion is the one worth carrying: this is why the technique is called the warm needle and not the hot needle (Huang VC, Sheu TW, Acupunct Electrother Res 2008;33(3–4):169–178, PMID 19301627). It is a physical study of heat transfer, not a clinical one, and it establishes nothing about effect — but it is one of very few studies anywhere in this literature that models a named point, and it settles a question readers frequently ask about burns.

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 lower-leg 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 GB-38, 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.

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 find that serious events concentrate at points over the chest, abdomen, neck and orbit, and are attributed chiefly to improper technique (J Altern Complement Med 2012;18(10):892–901, PMID 22967282; Bull World Health Organ 2010;88(12):915–921C, PMID 21124716, PMC2995190). GB-38 is in none of those groups.

Source: Sacred Lotus sources & references (existing needling and location records; the GB-34 record queried directly); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 455, surface and deep anatomy of the lateral lower leg); Chinese Acupuncture & Moxibustion (pp. 219–220); PMID 24280473; PMID 19301627; 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 Fu mean?

Yang Fu means "Yang Assistance" — yang, the yang aspect, and fu, to assist, support or act as an aide. Sacred Lotus sources & references translate it exactly that way. The name has a double reading and both are useful. Anatomically, the lower leg has two bones and the classical texts called the slender outer one — the fibula — the "assistant bone", fu gu: it supports the tibia rather than bearing the body's weight itself. GB-38 lies against the front edge of that assistant bone on the yang, outer surface of the leg, so "Yang Assistance" is a location instruction. Read the other way, yang names the channel — the Gall Bladder Channel of Foot Shao Yang — and fu names what the point does for it.

The lower leg carries a small cluster of such names within a few cun of one another, all held in Sacred Lotus sources & references: Guang Ming GB-37, "Bright Light", at five cun; Yang Fu GB-38, "Yang Assistance", at four cun; and Xuan Zhong GB-39, "Suspended Bell", at three cun. Three consecutive cun, three quite different images, and three different point classifications.

Is GB-38 the tonification point or the sedation point of the Gall Bladder channel?

GB-38 is the sedation (child) point of the Gall Bladder channel. The tonification (mother) point is GB-43 Xia Xi, the Water point. This is worth working out from first principles rather than taking on trust, and the derivation below was made from the element assignments held in our own records rather than carried over from any summary. It confirms the derivation our GB-43 record made from the other side — that record named GB-38 as the sedation point, and re-deriving it here reaches the same answer.

The reasoning has two layers, and separating them is what makes it stick.

The first layer is the five-shu position. GB-38 is the Jing-River point: the fourth of the five, the place the Ling Shu describes as the qi flowing freely in its channel like a river in its course. That is a statement about indication, and it tells you nothing about tonification or sedation.

The second layer is the element. On yang channels the Jing-River point is a Fire point; on yin channels it is a Metal point — which is why Ling Dao HT-04 and Jing Qu LU-08, both held here, are Jing-River and Metal points while Yang Fu on this yang channel is Jing-River and Fire. The Gall Bladder is a yang channel of the Wood phase. Now apply the rules:

• In the generating cycle, Water produces Wood and Wood produces Fire. So the mother of Wood is Water and the child of Wood is Fire.
• Under the mother-child rule, a channel is supplemented through its mother point and drained through its child point. On the Gall Bladder channel that gives: tonification (mother) point — GB-43 Xia Xi, the Ying-Spring and Water point; sedation (child) point — GB-38 Yang Fu, the Jing-River and Fire point. This page.
• The horary (self) point is the one whose element matches the channel's own: GB-41 Zu Lin Qi, Wood on a Wood channel.
• And in the controlling cycle Wood controls Earth, so GB-34 Yang Ling Quan, the He-Sea and Earth point, is the channel's controlled-element point — neither mother nor child.

The distinction students most often get wrong is assuming that a Fire point must be a heat-adding point, or that a heat-clearing point cannot be a Fire point. It depends entirely on the channel's own element. On the Gall Bladder, a Wood channel, Fire is the child, so the Fire point drains — and GB-38's first recorded action, clearing Gall Bladder channel heat, is exactly what the mother-child rule predicts. On the Heart, a Fire channel, the Fire point HT-08 Shao Fu is Fire on Fire and is the horary point, neither mother nor child. On the Liver, the yin Wood channel paired with this one, the Fire point is LIV-02 Xing Jian at the Ying-Spring position — also the child, and also that channel's sedation point. Liver and Gall Bladder are both Wood, so both are drained through their Fire points; they simply fall at different five-shu positions because one channel is yin and the other yang. Our LU-05, LIV-02, LIV-08, HT-03, HT-07, HT-08, P-08, SJ-10 and GB-43 records each set out the same rule from their own side, and every one of them arrives at it the same way: five-shu position gives the classical indication, the element's relationship to the channel gives the tonification-sedation role, and the two coincide only by arithmetic.

Is there research on GB-38 Yang Fu?

GB-38 has no clinical trial of its own, and this must be said plainly. What it does have is unusual: two studies in which the point itself is the named object of physical investigation — one modelling heat transfer at GB38 during warm needling, one examining GB38 by ultrasound as part of a validation of five-shu insertion depths. Neither is a trial, and neither says anything about whether the point works.

• Heat transfer at GB38, modelled and measured. An engineering study built a numerical model of the warm (moxa-heated) needle in the calf around the GB38 acupoint, validated against infrared camera measurement, and found that the temperature falls from about 200 °C at the burning moxa to about 36 °C at the skin, with tissue immediately beside the needle only about one degree warmer than tissue elsewhere (Acupunct Electrother Res 2008;33(3–4):169–178, PMID 19301627). It is described in full under needling. A physics paper about a named point, which is rare enough to be worth having.
• Ultrasound validation of the five-shu insertion depths, naming GB38. A pilot study examined the anatomical structures lying within the recorded insertion depth ranges of the five phase points using colour Doppler ultrasound, and placed GB38 among the points that "required careful insertion" rather than among those whose recorded depth ranges needed modifying (Complement Ther Med 2013;21(6):641–648, PMID 24280473). Also described under needling. A pilot, with no per-point figure available to us.
• A clinical trial in which GB-38 is one of nine points. Thirty men with mild-to-moderate peripheral artery disease and intermittent claudication were randomised to drug treatment alone or drug treatment plus gallium-aluminium-arsenide laser applied at nine acupuncture points — LIV-02, ST-41, BL-40, BL-60, BL-61, GB-30, GB-34, GB-38 and GB-40 — twice weekly for five weeks. The laser group improved on the Edinburgh Claudication Questionnaire and increased six-minute walk distance from 214 ± 60 to 318 ± 77 metres (Hong Kong Physiother J 2022;42(1):31–40, PMID 35782701, PMC9244600). This was laser stimulation, not needling, in thirty men at a single centre, using nine points; the result belongs to the protocol and nothing in it is attributable to GB-38.

What is missing should be said plainly: we could locate no randomised trial of GB-38 alone, no sham-controlled study of it, and no clinical study in which it is the point under test — including for its leading indication, one-sided headache. Rather than cite whole-protocol trials as though they concerned this point, the accurate statement is that GB-38's standing rests on its classification as the Jing-River, Fire and sedation point of the Gall Bladder channel and on long clinical use.

How does GB-38 compare with the points around it?

The outer lower leg carries four Gall Bladder points in a short span, and their classifications are what separate them. Wai Qiu GB-36, at seven cun, is the channel's Xi-Cleft point — the acute-and-painful choice. Guang Ming GB-37, at five cun, is the Connecting point and the channel's eye point, and our own record for it is one of the fuller ones in this library. Yang Fu GB-38, at four cun, is the Jing-River, Fire and sedation point. Xuan Zhong GB-39, at three cun, is the Hui-Meeting point for marrow, reached for in bone and marrow disorders and in neck stiffness. Four points, four different classifications, within four cun. Below them, Qiu Xu GB-40 in front of the outer ankle is the Yuan-Source point; above them, Yang Ling Quan GB-34 below the knee is the He-Sea and Earth point and the Hui-Meeting point of the sinews, and is the region's dominant point. Across on the paired yin channel, Xing Jian LIV-02 is the Liver's Fire and sedation point — GB-38's structural counterpart on the other Wood channel, arrived at by the same rule from the opposite polarity. And on the partner Shao Yang channel of the arm, Zhi Gou SJ-06 is the other yang Jing-River and Fire point of the pair, though on a Fire channel it is the horary point rather than the sedation point. All are held in Sacred Lotus sources & references.

Source: Sacred Lotus sources & references (name, translation, channel, Jing-River & Fire classification, the complete Gall Bladder five-shu series with element assignments, and the GB-34, GB-36, GB-37, GB-39, GB-40, GB-41, GB-43, GB-44, LIV-02, LIV-08, SJ-06, SJ-10, HT-04, HT-08, LU-05 and LU-08 records, all queried directly); Deadman & Al-Khafaji, A Manual of Acupuncture (p. 455); Chinese Acupuncture & Moxibustion (pp. 219–220); Ling Shu (Spiritual Pivot), on the five-shu points; Nan Jing (Classic of Difficulties), on the five-shu indications and the mother-child rule; PMID 19301627; PMID 24280473; PMID 35782701 (PMC9244600) — each verified resolvable and checked for retraction status before citation; cross-referenced against multiple online sources.