BL-31 (Shang Liao) Upper Bone Hole

What does BL-31 Shang Liao do?

BL-31 regulates the lower jiao and facilitates urination and defecation, regulates menstruation and stops leucorrhoea, and benefits the lumbar region and legs. It sits over the first hole in the sacrum, and it is the first of the four liao points.

• Regulates the lower jiao and facilitates urination and defecation
• Regulates menstruation and stops leucorrhoea
• Benefits the lumbar region and legs

The eight liao points, verified complete in our own records. Four points on each side, over the four posterior sacral foramina — the ba liao, or “eight holes”. Querying our own location records returns the full set with no gap:

• BL-31 Shang Liao — Upper Bone Hole, over the first posterior sacral foramen (this point)
• BL-32 Ci Liao — Second Bone Hole, over the second
• BL-33 Zhong Liao — Middle Bone Hole, over the third
• BL-34 Xia Liao — Lower Bone Hole, over the fourth

An overlap that is real and is disclosed rather than smoothed over. Our records give BL-31 and BL-34 word-for-word identical action lists — all three actions, in the same order, in the same words. That is not an error in either record; it reflects source material that treats the liao points as a functional group rather than as four distinct points. What separates them is which foramen they sit over, and this library says so instead of manufacturing differences. The same approach is taken across the BL-03 to BL-09 scalp run.

Its second classification: our record also gives BL-31 as a Meeting Point of the Bladder and Gallbladder channels, a designation it shares with BL-34.

Source: Sacred Lotus sources & references (channel, category, action and location records; all four liao points queried and their action records compared word for word against our own data), cross-referenced against multiple online sources.

What is BL-31 Shang Liao used for?

BL-31 is used for low back pain, difficult urination, constipation, irregular menstruation, abnormal vaginal discharge and uterine prolapse. Our own indication record is reproduced here in full.

• Low back pain
• Dysuria (difficult or painful urination)
• Constipation
• Irregular menstruation
• Morbid leucorrhoea (abnormal vaginal discharge)
• Prolapse of the uterus

Five of the six are pelvic, and that is the sacrum’s own anatomy. The nerves supplying the bladder, the rectum and the reproductive organs leave the spinal canal through the sacral foramina — the very holes these points sit over. A group of points whose recorded indications are urinary, bowel and gynaecological, positioned directly over the openings those nerves pass through, is one of the closer correspondences between classical point location and modern anatomy in the whole library. It is stated here as a correspondence, not as a mechanism.

An honest note. Difficulty passing urine, and especially an inability to pass urine, requires urgent medical assessment. Abnormal vaginal discharge, uterine prolapse, and any change in menstrual pattern require medical assessment rather than repeated self-treatment. Low back pain with leg weakness, saddle numbness or any change in bladder or bowel control is a medical emergency. This record documents classical use and should not delay any of that.

How it is combined. With BL-32, BL-33 and BL-34 — the liao points are usually used as a group rather than singly, which is consistent with how little separates their records. With REN-03 Zhong Ji and REN-04 Guan Yuan on the lower abdomen, the front-and-back pairing for the pelvis. With SP-06 San Yin Jiao distally. With DU-20 Bai Hui for prolapse, the classical top-and-bottom pairing for sinking qi. All held here.

Source: Sacred Lotus sources & references (indication and location records; the BL-32, BL-33, BL-34, REN-03, REN-04, SP-06 and DU-20 records queried from our own data), cross-referenced against multiple online sources.

Where is BL-31 Shang Liao located?

BL-31 sits over the FIRST posterior sacral foramen — the highest of the four holes in the back of the sacrum, which can be felt as a small depression.

• Over the first posterior sacral foramen
• BL-32, BL-33 and BL-34 follow below it over the second, third and fourth foramina
• BL-27 to BL-30, the sacral Back-Shu points, lie on the line lateral to them

These points have real holes to find, which is rare on the back. Most points on the trunk are located by counting spinous processes and measuring outward — a chain in which one miscount displaces everything below it. The posterior sacral foramina are palpable openings in bone, and the classical descriptions locate them by feel. That places BL-31 in the small group of points in this library with a genuine bony landmark, alongside DU-02 at the sacral hiatus, ST-02 at the infraorbital foramen and BL-09 at the occipital protuberance.

The practical caveat. The foramina are shallower and less distinct in some people than in others, and the first one — BL-31’s — sits highest, closest to where the sacrum joins the ilium. Sources differ on how precisely it should be found by measurement as against by palpation, and our own record gives it simply by the foramen.

On the name. “Shang Liao” means Upper Bone Hole. Liao is a hole or crevice in bone, and it names all four points here as well as GB-01 Tong Zi Liao beside the eye and SI-18 Quan Liao on the cheek — in every case a point sitting at or beside an opening or hollow in bone. It is one of the most consistently used descriptive elements in the whole naming system.

Source: Sacred Lotus sources & references (location and translation records, retained unchanged; the BL-27 to BL-34, DU-02, ST-02, BL-09, GB-01 and SI-18 records queried from our own data).

• A Manual of Acupuncture (p. 292): Over the first posterior sacral foramen.
• Chinese Acupuncture and Moxibustion (p. 182): On the sacrum, at the midpoint between the posterosuperior iliac spine and the posterior midline, just at the first posterior sacral foramen.

How is BL-31 Shang Liao needled?

Our own record states perpendicular insertion of 0.8–1.2 inches, with moxibustion applicable — a deeper recorded range than most points on the back, and the reason is that the needle is directed toward an opening rather than onto solid bone. What follows is a neutral record of what the reference literature documents. It is not instruction, and this page does not teach technique.

• Angle and depth as recorded: perpendicular, 0.8–1.2 inches — compare 0.3–0.5 inch at the thoracic back points and 0.5–1.0 inch on the lumbar midline.
• Moxibustion: recorded as applicable.
• Regional anatomy: the erector spinae and the origin of gluteus maximus overlie the sacrum; the first posterior sacral foramen transmits the posterior ramus of the first sacral nerve with accompanying vessels; the sacral canal and its contents lie deep to the foramen, and the pelvic cavity beyond the bone.

Why the depth is greater here, stated plainly. At most points on the back the vertebral arch or the rib stops the needle. Over a sacral foramen there is an opening in the bone, and the recorded depth reflects that the needle can enter it. Our DU-02 record describes the same situation at the sacral hiatus, and draws the same conclusion: where bone does not stop the needle, the recorded depth is doing the work instead. This is also the reason the recorded angle is specified.

Hazard, stated proportionately. There is no pleura here and no great vessel at the surface. The structures that matter are the sacral nerve roots passing through and below the foramen, and the pelvic contents beyond the sacrum — neither of which the recorded depth reaches, and both of which are the reason the recorded depth is a range with a stated top.

What is not claimed. No study measuring a safe depth at BL-31 could be located, and none is borrowed. The paediatric CT study this library uses covers 23 points on the trunk and shoulder, from DU-09 upward, and does not reach the sacrum. No case report naming BL-31 was located.

Source: Sacred Lotus sources & references (needling record, retained unchanged, and the recorded depths at the thoracic and lumbar points compared; the DU-02 record and the point list of PMID 26922245 / PMC4769822 queried from our own data), cross-referenced against multiple online sources; regional anatomy from standard anatomical description.

Is there research on BL-31, and what should a reader know?

No trial isolates BL-31. Where the point appears it is almost always as one of the liao group in a pelvic or obstetric protocol, and a study that includes a point in a protocol is not evidence about that point.

The liao points as a group do appear in the labour and dysmenorrhoea literature, usually as “BL-31 to BL-34” or as ba liao, needled together. That is worth knowing precisely because it means the evidence, such as it is, attaches to the group and not to any single foramen. Nothing in that literature is claimed here as evidence about BL-31 alone.

What this page can state with confidence. BL-31 sits over the first posterior sacral foramen, one of the four liao points whose complete set is verified in our own records. Its recorded action list is word for word identical to BL-34’s, which is a real feature of the source material and is disclosed rather than papered over. Its recorded depth of 0.8–1.2 inches is deeper than most back points because the needle is directed at an opening in bone rather than onto it. And five of its six indications are pelvic — a close correspondence with the nerves that leave the sacrum through these very holes.

A note on searching for it. “BL 31”, “UB 31” and “Shangliao” searches return protocol trials and unrelated material — and there is a specific trap here: trials naming this point usually used all four liao points together, so a result matching “BL-31” frequently describes an eight-point treatment. Our library codes this channel BL- while some sources use UB-. Any claim attached to this point should be checked against what a study actually used.

Source: Sacred Lotus sources & references (location, action and indication records; all four liao points and their action records queried and compared against our own data).