Acupuncture
View all acupuncture points on this meridian and explore the channel pathway.
View meridian
EX-B-9
Needle Depth
2–3 cun
Needle Angle
90° (Perpendicular)
Body Area
Hip / Gluteal, Back — Sacral
Location
At the center of the buttock, 3.5 cun lateral to the posterior midline, on the level of the 4th sacral foramen.
Main Actions
- Opens the local Channel and Luo Vessels
Indications
Sciatica
Lower limb paralysis
Buttock pain
Hip pain
Lumbar pain radiating to leg
Piriformis syndrome
Numbness in lower limbs
Lower back pain
Sacral pain
Difficulty walking
Weakness of lower extremities
Atrophy of leg muscles
Commentary
Tunzhong EX-B is not an official Extra point.
Classical Sources
Tunzhong (臀中) is an extra point that was developed through empirical clinical practice for treating disorders of the buttock and lower limb. While not appearing in the earliest classical texts, it has been documented in modern acupuncture compilations as an effective point for sciatica and lower extremity paralysis.
The point name literally means "Center of the Buttock," describing its anatomical location in the middle of the gluteal region.
How to Locate
First identify the Tuffier's line which connects the highest points of the iliac crest. The spinous process of the 4th lumber vertebra (L4) mostly falls on this line. Then palpate in an inferior direction, passing L5, and reach the most superior sacral spinous process. Palpate in a lateral direction on the level of the sacral processes for the depression of the sacral foramina. Tunzhong EX-B is at the same level as the 4th foramina and 3.5 cun lateral to the posterior midline.
Caution
Due to the deep needling required (2-3 cun), practitioners should be mindful of the sciatic nerve which passes through this region. The needle should be inserted carefully to avoid direct contact with the nerve. Patients may experience significant radiating sensation which is normal and indicates proper stimulation of the sciatic nerve pathway. If sharp, shooting pain occurs, the needle should be slightly withdrawn and redirected. Use caution during pregnancy as this point is in the sacral/gluteal region.
Needle Angle
90° (Perpendicular)
Depth Category
Deep
Standard Depth
2–3 cun
Needling Directions
Vertically 2–3 cun.
Expected Deqi Sensation
Deqi sensation typically manifests as a deep ache or distension in the buttock that may radiate down the posterior or lateral aspect of the thigh toward the knee or foot, following the course of the sciatic nerve. Patients often describe an electric or tingling sensation radiating downward. Due to the depth of insertion through the gluteal muscles, the sensation may take a moment to develop.
Moxibustion
Recommended
Duration: 10–15 minutes
Cupping
Recommended
Bloodletting
N/A
Gua Sha
Recommended
Related Resources
Browse All Points
Explore the complete collection of acupuncture points across all meridians.
View all meridians