BL-64 (Jing Gu) Capital Bone

What does BL-64 Jing Gu do?

Jing Gu BL-64 is the Yuan (Source) point of the Bladder channel of Foot Tai Yang — the point at which the original qi of that channel is said to surface and collect — and it sits on the outer edge of the foot, in the hollow just in front of and below the bony bump halfway along it. Sacred Lotus sources & references record its actions as clearing the head and eyes and eliminating wind, calming the spirit, and relaxing the sinews, activating the channel and alleviating pain. Source points regulate rather than merely tonify or drain, which is what allows one point at the foot to serve a channel that runs from the eye, over the whole skull, down the entire back and to the little toe.

• Clears the head and eyes and eliminates wind — the defining action, and the reason a point on the side of the foot is recorded for headache and for the eyes. The Bladder channel is the longest in the body: its described course begins at the inner corner of the eye, crosses the top of the head, and runs down the back of the neck and the whole spine. BL-64 is the Source point of that channel, and the head is where its territory begins.
• Relaxes the sinews, activates the channel and alleviates pain — the channel action along the same long course: rigidity of the neck, pain and stiffness in the low back and the back of the thigh, and pain in the foot itself.
• Calms the spirit — recorded for agitated and disordered mental states and for epilepsy. Tai Yang's connection to the head, and the Bladder channel's described branch entering the brain at the nape, is the traditional rationale.
• Regulates the Bladder channel in either excess or deficiency — 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 balances rather than only reinforcing or only draining.
• Serves as a diagnostic point — like all Source points, tenderness or a change in the hollow at BL-64 is read as referring to its own channel and organ, so the point is palpated before it is chosen. Modern work has taken that idea literally enough to measure it: see the research section below.

Source: Sacred Lotus sources & references (channel, Yuan Source classification, and the existing action record); Deadman & Al-Khafaji, A Manual of Acupuncture, p. 323; Chinese Acupuncture & Moxibustion, p. 190; Source-point scheme per Ling Shu (Spiritual Pivot), Chapter 1; cross-referenced against multiple online sources.

What is BL-64 Jing Gu used for?

BL-64 is used along the Bladder channel's course rather than for the bladder organ — chiefly for headache and a rigid neck at one end, and for the low back and leg at the other. The indications carried in Sacred Lotus sources & references are set out below. They describe traditional use, not proven treatment.

• Headache
• Rigidity and pain of the neck
• Pain in the lower back
• Pain in the thigh and along the back of the leg
• Epilepsy
• Redness, pain or clouding of the eyes
• Nasal congestion and nosebleed
• Pain and swelling of the outer border of the foot
• Agitation, palpitations and disordered mental states
• Febrile disease without sweating, in the classical record

A note on what BL-64 is not for. Despite being the Source point of the Bladder channel, BL-64 is not the point reached for in urinary complaints. The bladder organ's own points are elsewhere — REN-03 Zhong Ji, the Front-Mu point on the lower abdomen, and BL-28 Pang Guang Shu, the Back-Shu point on the sacrum, both held in Sacred Lotus sources & references. What BL-64's indications describe is the channel's route: the eye, the head, the neck, the spine, the back of the leg and the outer foot. That gap between organ and channel is entirely normal in point theory — the Small Intestine channel's points are similarly not digestive points — and it is worth stating so that a reader does not expect the point to do something the sources never claim for it.

Source: Sacred Lotus sources & references (existing indication record, and the REN-03 and BL-28 records); Chinese Acupuncture & Moxibustion, p. 190; Deadman & Al-Khafaji, A Manual of Acupuncture, p. 323; cross-referenced against multiple online sources.

Where is BL-64 Jing Gu, and how is it used in practice?

Jing Gu lies on the outer border of the foot, in the depression just in front of and below the prominent bump about halfway along that edge — the flare at the base of the little toe's long bone, which is easy to feel and often easy to see. The point sits on the border between the pale sole skin and the darker skin of the top of the foot, what the texts call the junction of the red and the white. Sacred Lotus sources & references hold two location records for it, one describing the site below that tuberosity at the red-and-white junction and one describing the depression anterior and inferior to it; they describe the same hollow and neither has been altered here.

Which points is BL-64 combined with?

• With KI-04 Da Zhong — the Yuan-Luo pairing, and the most theoretically important combination BL-64 has. The rule joins a channel's Source point to the Connecting (Luo) point of its interior-exterior partner: the Bladder's Source point at the outer foot with the Kidney's Connecting point at the inner heel. Sacred Lotus sources & references confirm KI-04 as the Kidney channel's Luo point. This is not merely a textbook convention — it is the one BL-64 combination that has been examined anatomically, and the finding is reported under research below.
• With BL-28 Pang Guang Shu — the Shu-Yuan pairing, joining the Source point to its own organ's Back-Shu point on the sacrum. The other structured combination the Source classification makes available.
• With BL-58 Fei Yang — the Bladder channel's own Connecting point on the calf, used with BL-64 as a within-channel Yuan-Luo arrangement.
• With BL-60 Kun Lun and BL-62 Shen Mai — its immediate neighbours around the outer ankle, used together for the neck, the low back and local foot complaints. The three are effectively a cluster, and the pain-threshold study described below tested exactly this group.
• With BL-65 Shu Gu — the Shu-Stream and Wood point of the channel, immediately distal to BL-64 along the same border of the foot. On a yang channel these are two different points with two different classifications sitting a fingerbreadth apart, which is the clearest illustration available of the yin/yang Source-point rule set out in the notes below. They are also the pair used together in the electroacupuncture research described further down.
• For headache — with BL-60 Kun Lun, and with the local points at the back of the head. A randomised trial of acupuncture for headache in the recovery phase of ischaemic stroke selected points by the region of the headache, and named Jinggu BL-64 with Kunlun BL-60 for occipital headache specifically (PMID 31724347), which is exactly the Tai Yang territory the classical record assigns the point.
• For the low back — with BL-40 Wei Zhong at the back of the knee and BL-23 Shen Shu beside the lumbar spine, the standard Bladder-channel arrangement in which BL-64 supplies the distal end.

Where does BL-64 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 — BL-64 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.

Source: Sacred Lotus sources & references (both location records, Yuan Source classification, the full twelve-point Source set queried directly, and the KI-04, BL-23, BL-28, BL-40, BL-58, BL-60, BL-62 and BL-65 records); Deadman & Al-Khafaji, A Manual of Acupuncture, p. 323; Chinese Acupuncture & Moxibustion, p. 190; PubMed PMID 31724347; cross-referenced against multiple online sources.

Where is BL-64 located?

• A Manual of Acupuncture (p. 323): On the lateral side of the foot, in the depression anterior and inferior to the tuberosity of the fifth metatarsal bone.
• Chinese Acupuncture and Moxibustion (p. 190): Below the tuberosity of the fifth metatarsal bone, at the junction of the red and white skin.

How is BL-64 Jing Gu needled in the textbooks?

Reference record only — this sets out what the standard texts document, not instruction for a reader. Sacred Lotus sources & references record perpendicular insertion of 0.3 to 0.5 inch at BL-64, with moxibustion noted as applicable. Deadman & Al-Khafaji record a comparable shallow perpendicular range at the same site. It is a short range because there is very little tissue between the skin of the outer foot and the bone beneath it.

• Angle documented: perpendicular into the depression in front of and below the tuberosity of the fifth metatarsal bone.
• Depth documented: approximately 0.3 to 0.5 inch.
• Moxibustion: documented as applicable.
• Sensation: the point is characteristically tender, which is a property of Source points generally and part of why they are palpated diagnostically.

Safety reference, stated plainly: BL-64 is a low-hazard point. There is no thoracic, abdominal or cranial structure anywhere near it. None of the pneumothorax caution that governs points over the chest and upper back applies here, none of the depth-and-direction caution that governs the points over the foramen magnum applies, and none of the pregnancy or bladder cautions that govern the lower-abdominal points applies. Saying that plainly is more useful to a reader than a generic warning, and it is one of the reasons the point is freely used.

What does bound the recorded depth is entirely local and superficial. Immediately deep to the skin lie the abductor digiti minimi muscle and the small muscles of the outer border of the foot, with the shaft and tuberosity of the fifth metatarsal bone as the floor — which is why the recorded range is short. Branches of the lateral dorsal cutaneous nerve and the lateral plantar nerve, and the small dorsal and plantar vessels of the outer foot, run close to the point, so a radiating sensation along the outer border of the foot and superficial bruising are the ordinarily documented occurrences. Two systematic reviews of the safe-needling-depth literature concluded that measured depths for the same point vary greatly between subject groups and between measuring 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); a textbook figure is a central estimate, not a guarantee, even at a shallow point.

Risk in proportion. A meta-analysis of prospective clinical studies estimated serious acupuncture-related adverse events at approximately 1 per 10,000 patients, with about half of all recorded events being bleeding, pain or flare at the needle site (Bäumler P et al., BMJ Open 2021;11:e045961, PMID 34489268). At a point like BL-64, minor local events are essentially the whole of the risk profile. Standard clean-needle practice applies. Acupuncture is carried out only by a qualified, licensed practitioner; this record documents the literature and is not a technique guide.

Source: Sacred Lotus sources & references (existing needling record); Deadman & Al-Khafaji, A Manual of Acupuncture, p. 323 (surface and deep anatomy of the lateral border of the foot); Chinese Acupuncture & Moxibustion, p. 190; PubMed PMID 21417806; PMID 23935678; PMID 34489268 — each verified resolvable and checked for retraction status before citation.

What does the name Jing Gu mean?

Jing Gu means "Capital Bone" — jing, a capital city, and gu, a bone. The name is not a metaphor for anything the point does; it is the old anatomical name of the bone the point sits against. The flared tuberosity at the base of the fifth metatarsal — the prominent bump halfway along the outer border of the foot — was itself called the jing gu in the classical anatomical vocabulary, and the point simply takes the landmark's name. Why "capital" is not certainly recoverable, though the sense of jing as something large, principal or commanding fits a bone that stands out as the most conspicuous landmark on that edge of the foot. It is also rendered "Capital Bone", "Metropolis Bone" and "Great Bone" in different translations.

The same character appears elsewhere in the point names held in Sacred Lotus sources & references: GB-25 Jing Men, "Capital Gate", the Front-Mu point of the Kidney on the flank, uses the same jing. Point names that borrow the vocabulary of cities, gates and roads are common in the canon, and reading them together is one of the more reliable ways of remembering where points sit.

Why does the Yuan (Source) classification matter at BL-64?

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, which joins a channel's Source point to the Connecting point of its partner channel (here BL-64 with KI-04 Da Zhong), and the Shu-Yuan pairing, which joins the Source point to the organ's Back-Shu point (here BL-28 Pang Guang Shu). Knowing BL-64 is the Source point is what makes those combinations available.

Why is the Source point separate from the Shu-Stream point on a yang channel?

This is one of the genuinely useful pieces of five-shu theory, and BL-64 is the clearest place to see it. 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 of its own. BL-64 Jing Gu is the Bladder channel's Source point and carries no element; BL-65 Shu Gu, a short distance distal to it on the same border of the foot, is the channel's Shu-Stream and Wood point. Two points, two roles, a fingerbreadth apart.

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. Whatever one makes of the rationale, the practical consequence is concrete: on a yin channel, choosing the Source point and choosing the Shu-Stream point are the same act, while on a yang channel they are two different choices. The Bladder channel's five-shu series held in Sacred Lotus sources & references runs BL-67 Zhi Yin (Jing-Well, Metal) at the little-toe nail, BL-66 Tong Gu (Ying-Spring, Water), BL-65 Shu Gu (Shu-Stream, Wood), BL-60 Kun Lun (Jing-River, Fire) behind the outer ankle and BL-40 Wei Zhong (He-Sea, Earth) at the back of the knee — with BL-64 sitting outside that series as the Source point, and BL-63 Jin Men beside it as the Xi-Cleft point.

Is there research on BL-64 Jing Gu?

The point-specific research on BL-64 is thin, and it would be misleading to suggest otherwise. What exists is unusual, though: rather than clinical trials, it consists largely of studies that set out to test the classical theory attached to this point — the Yuan-Luo pairing, the diagnostic use of Source points, and point specificity.

• The Yuan-Luo pairing, tested anatomically. A neural-tracing study injected two differently coloured cholera-toxin tracers at the rat equivalents of Jinggu BL-64 — described as the border between red and white flesh distal to the tuberosity of the fifth metatarsal, which matches our own location record — and Dazhong KI-04, at the inner heel. The labelled sensory neurons for both points were found in the same dorsal root ganglia, L3 to L6 and concentrated at L4 and L5, with a small number of dual-labelled neurons — single cells innervating both points — and the motor neurons for both distributed in the same segments of the spinal ventral horn (Zhen Ci Yan Jiu 2011;36(4):262–7, PMID 21942179). The authors present this as a neuroanatomical basis for combining Source and Connecting points of paired channels. Three rats, so the numbers are very small, and shared segmental innervation is a weaker claim than it first sounds — but it is a rare case of a classical combination rule being examined directly, and it concerns this exact pair.
• 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, and among the points whose values changed significantly after surgery on both sides were Jinggu BL-64, LU-09, P-07, SP-03, LIV-03, KI-03, GB-40 and ST-42 — a pattern the authors read as involving the yang channels described as entering the brain (Zhen Ci Yan Jiu 2010;35(1):52–5, PMID 20458908). An observational measurement study, not a test of treatment, and it is cited for what it is.
• Point specificity, and an honest negative. Pain thresholds were measured with an electronic von Frey anaesthesiometer in 66 healthy volunteers at points down the Bladder channel of the lower leg and foot. Among BL-65 Shu Gu, BL-64 Jing Gu, BL-60 Kun Lun and BL-57 Cheng Shan there was no significant difference in pain threshold — but all four had significantly lower thresholds than a non-acupoint one cun to the side of BL-60 (Zhen Ci Yan Jiu 2013;38(1):68–72, PMID 23650804). Read plainly: this supports the acupoint regions being measurably different from adjacent non-points, and does not support BL-64 being distinguishable from its own neighbours.
• Animal mechanism work using BL-64 with BL-65. Low-frequency electroacupuncture applied between Jinggu BL-64 and Shugu BL-65 in anaesthetised rats was followed by increased neuronal nitric oxide synthase expression in the gracile nucleus of the brainstem — the relay for sensation from the hind limb (Acupunct Electrother Res 2002;27(3–4):157–69, PMID 12638736, DOI 10.3727/036012902816026022). Animal work on a two-point stimulation; it demonstrates a central response to stimulation at these sites, not a clinical effect.
• Clinical use. A brief clinical report describes acupuncture at Jinggu BL-64 for back fasciitis (Zhongguo Zhen Jiu 2015;35(2):194, PMID 25854035). It is a single page with no abstract and no extractable outcome data, recorded here only as evidence that single-point use at BL-64 appears in the clinical literature. Separately, a randomised trial of acupuncture for headache in the recovery phase of ischaemic stroke selected points by headache region and used BL-64 with BL-60 for occipital headache (Zhongguo Zhen Jiu 2019;39(11):1149–53, PMID 31724347) — the point chosen for exactly the territory the classical record assigns it, within a larger protocol that does not isolate it.

BL-64's standing rests on its classification as the Source point of the Bladder channel and on long clinical use, not on modern trial evidence. We hold no controlled trial testing BL-64 on its own for headache, neck rigidity, back pain or any other indication, and we do not cite whole-protocol studies as though we did. The site does not claim that BL-64 treats headache, neck pain, back pain or epilepsy.

How does BL-64 compare with the points around it?

The outer border of the foot and ankle carries five Bladder points in a short span, and their classifications are what separate them. BL-60 Kun Lun sits behind the outer ankle bone and is the Jing-River and Fire point — the other main local point for the ankle and the classical partner for neck and back pain. BL-62 Shen Mai lies just below the outer ankle bone and is the Confluent point of the Yang Motility Vessel, paired with SI-03 Hou Xi. BL-63 Jin Men, immediately behind BL-64, is the channel's Xi-Cleft point and a Meeting Point with the Yang Linking Vessel — the point for acute and painful presentations. BL-64 Jing Gu is the Source point. BL-65 Shu Gu, just distal, is the Shu-Stream and Wood point. Five points, five different classifications, all within a few centimetres — which is the whole reason the categories exist. Across the ankle, KI-03 Tai Xi is the Source point of the paired Kidney channel and KI-04 Da Zhong its Connecting point, BL-64's Yuan-Luo partner. All are held in Sacred Lotus sources & references.

Source: Sacred Lotus sources & references (name, both location records, Yuan Source classification, the full twelve-point Source set and the Bladder five-shu series queried directly, and the BL-40, BL-57, BL-58, BL-60, BL-62, BL-63, BL-65, BL-66, BL-67, KI-03, KI-04, SI-03, GB-25 and BL-28 records); Deadman & Al-Khafaji, A Manual of Acupuncture, p. 323; Chinese Acupuncture & Moxibustion, p. 190; Ling Shu (Spiritual Pivot), Chapter 1, on the Source points; PubMed PMID 21942179, 20458908, 23650804, 12638736, 25854035, 31724347 — each verified resolvable and checked for retraction status before citation; cross-referenced against multiple online sources.