SI3 Back Stream

Reviewed by · Licensed Acupuncturist & TCM Physician · Last reviewed June 2026

SI3 (Houxi, “Back Stream”) is the Shu-Stream point of the Small Intestine Channel Meridian. It is located on the ulnar side of the hand, proximal to the metacarpophalangeal joint of the little finger, at the end of the transverse palmar crease when the fist is clenched. It activates the meridian, alleviates pain, and benefits the neck and back.

Location

On the ulnar side of the hand, proximal to the metacarpophalangeal joint of the little finger, at the end of the transverse palmar crease when the fist is clenched.

Needling

Perpendicular insertion 0.5-1 cun.

TCM functions

Activates the meridian, alleviates pain, and benefits the neck and back.

Indications

Headache, stiff neck, pain in the back and leg, lumbar sprain, tinnitus, deafness, malaria, epilepsy, night sweats, pain in the finger.

Shu-StreamConfluent of Du MaiCommand point of the occiput and neck

Clinical notes

SI3 is a highly versatile Shu-Stream point and the Confluent point of the Du Mai, making it a command point for the occiput, neck, and spine. It is indispensable for neck stiffness, back pain, and acute lumbar sprain, especially when aggravated by movement. It also clears wind and heat from the head, treating headaches, tinnitus, and eye pain, and is empirically used for night sweats when combined with HT6.

On the Small Intestine Channel channel

SI3 is one of 19 points on the Small Intestine Channel Meridian. Nearby points:

Frequently asked questions

Where is SI3 located?

SI3 (Houxi) is located on the ulnar side of the hand, proximal to the metacarpophalangeal joint of the little finger, at the end of the transverse palmar crease when the fist is clenched.

What is SI3 used for?

SI3 activates the meridian, alleviates pain, and benefits the neck and back. Common clinical indications include headache, stiff neck, pain in the back and leg, lumbar sprain, tinnitus, deafness, malaria, epilepsy, night sweats, pain in the finger.

How is SI3 needled?

Perpendicular insertion 0.5-1 cun.

Which meridian is SI3 on?

SI3 is a point on the Small Intestine Channel Meridian (Shǒu Tài Yáng Xiǎo Cháng Jīng).

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⚠️ This page is for general education and is not medical advice. Acupuncture is a traditional practice; evidence varies by condition and study quality, and individual results differ. It does not replace diagnosis or treatment by a licensed professional. Always consult a qualified acupuncturist or physician.