Bladder MeridianBL22

Sanjiaoshu 三焦兪

For reference only · not a substitute for diagnosis or treatment

Short answer

Low back (lumbar region), 1.5 cun out from the back midline at the level of L1.

Back-shu point of the Triple Energizer (Sanjiao)

See it in 3DRotate the body and peel back the skin to see the bones and muscles beneath.
Open the 3D Acupoint Map →

🖼See it in pictures

Sanjiaoshu — ① Where on the body? — **① Where on the body?**

Sanjiaoshu — Textbook view — skin on the left, muscle and bone underneath on the right — **Textbook view — skin on the left, muscle and bone underneath on the right**
Location and structures come from our 3D model; only the drawing style was refined with AI. Labels are added by us.

Sanjiaoshu — ② Up close — **② Up close**

Sanjiaoshu — ③ Under the skin — **③ Under the skin**
Vertebra l1 · Latissimus dorsi muscle · Serratus posterior inferior muscle · Longissimus thoracis muscle

Rendered straight from the 3D model at the computed location. The glowing ring marks Sanjiaoshu.

On this page

Where is Sanjiaoshu?
How do I find it on my body?
Before you press
How has it been used traditionally?
FAQ

1Where is Sanjiaoshu?

Low back (lumbar region), 1.5 cun out from the back midline at the level of L1.

The level is set by the lower edge of the L1 spinous process.

Beneath the point

Vertebra l1 · Latissimus dorsi muscle · Serratus posterior inferior muscle · Longissimus thoracis muscle

Our 3D measurement · In our 3D model: level with the lower tip of the L1 spinous process, 1.5 cun (30.9 mm; 1 cun = 20.63 mm) from the back midline.

2How do I find it on my body?

Find T12, halfway between the lower tip of the shoulder blade and the top of the iliac crest. The first spinous process below it is L1.
Take the height of the lower edge of that spinous process.
Press 1.5 cun out from the midline. Use the same width as on the upper back: half of the 3-cun midline-to-shoulder-blade distance.

Check · it is level with Huangmen (BL51) and, on the midline, with Xuanshu (GV5).

What is a “cun”?

A cun is a body-scaled unit of length. The precise way is to divide a bone length into equal parts (proportional bone cun); finger widths are a quick estimate.

📖 Words explained

serratus posterior inferior: A thin muscle deep in the lower back, under latissimus dorsi. It runs from the lower back and upper lumbar bones to the lowest four ribs.
longissimus thoracis: The back part of the middle column of erector spinae (longissimus). As its name says it is long, and it straightens the lower and middle back.
iliac crest: The curved bony ridge forming the top rim of the pelvis, under your palms when you put your hands on your hips. A line joining the highest points on both sides usually crosses the fourth lumbar spinous process.
spinous process: The bony spike sticking backward from the middle of each spine bone. The row of bumps you feel down the middle of the back is these, and they serve as the counting marks for back points.
latissimus dorsi: The broad muscle covering the lower back and sides. It runs from the lower back and pelvis, behind the armpit, to the humerus, and pulls the arm down and back, as in a pull-up.

3Before you press

⚠ Do not press when

Do not press this point during pregnancy.
Points over the low back and sacrum are traditionally avoided in pregnancy (WHO acupuncture safety guidelines, 1999).
Avoid broken or swollen skin and press only to a comfortable level.
Acupressure is not a substitute for medical care.

4How has it been used traditionally?

Classified as the back-shu point of the Triple Energizer (Zhenjiu Jiayi Jing) — a historical classification, not a claim of effect.
Classical texts count it as 'below the 13th vertebra', which is L1 today.

From traditional texts — not a claim of effect.

?FAQ

Where exactly is Sanjiaoshu?

Low back (lumbar region), 1.5 cun out from the back midline at the level of L1. The level is set by the lower edge of the L1 spinous process.

How do I find Sanjiaoshu?

Find T12, halfway between the lower tip of the shoulder blade and the top of the iliac crest. The first spinous process below it is L1. Take the height of the lower edge of that spinous process. Press 1.5 cun out from the midline. Use the same width as on the upper back: half of the 3-cun midline-to-shoulder-blade distance. it is level with Huangmen (BL51) and, on the midline, with Xuanshu (GV5).

Can I press it during pregnancy?

Do not press this point during pregnancy.

What should I watch out for?

Do not press this point during pregnancy. Points over the low back and sacrum are traditionally avoided in pregnancy (WHO acupuncture safety guidelines, 1999). Avoid broken or swollen skin and press only to a comfortable level. Acupressure is not a substitute for medical care.

← PreviousWeishu · BL21 Next →Shenshu · BL23

Sources

Location: WHO Standard Acupuncture Point Locations in the Western Pacific Region (2008), p. 110
Standard comparison: Chinese national standard GB/T 12346-2021 (Nomenclature and location of meridian points), p. 17 — same location
Korean anatomical terms: KMLE medical dictionary
Traditional-use cross-check: AcuAtlas dataset (CC BY 4.0)
Classification source: Zhenjiu Jiayi Jing vol. 3, sec. 8 (back-shu line, 1.5 cun)
Safety: WHO Guidelines on Basic Training and Safety in Acupuncture (1999), p. 20 — lumbosacral points in pregnancy

Positions computed from the WHO standard locations (2008) on Z-Anatomy (CC BY-SA 4.0) · BodyParts3D © DBCLS. For reference only — not a substitute for diagnosis or treatment. See a clinician if you are unwell.