Small Intestine Meridian
Separates the clear from the turbid — and runs a long, winding path across the shoulder blade.
Pathway
The Small Intestine meridian begins at the ulnar side of the little finger at SI-1 Shaoze. It runs along the ulnar edge of the hand and forearm, around the elbow, and up the posterior shoulder. It zigzags across the scapula at SI-11 Tianzong, then enters the supraclavicular fossa and internally connects with the heart, diaphragm, stomach, and small intestine.
A branch ascends the neck to the cheek, reaches the outer canthus, and enters the ear at SI-19 Tinggong. The channel's winding shoulder path is one reason it is associated with neck, shoulder, and scapular tension.
Role in TCM theory
- Separating the clear from the turbid (分清泌濁) — The small intestine is said to receive food from the stomach and separate the refined portion from waste, passing each onward.
- Fire pair with the Heart — Small intestine and heart share the Fire element and are described as interior–exterior partners; the tradition links digestive clarity with mental clarity.
- The scapular highway — Its long run across the shoulder blade makes it a traditional target for shoulder and neck patterns.
- An ear-and-face branch — The branch ending at the ear explains the channel's traditional association with ear and jaw discomfort.
Common acupoints on the Small Intestine meridian
| Point | Name | Location | Traditional use |
|---|---|---|---|
| SI-3 | Houxi (後溪) | At the ulnar end of the distal palmar crease, in the depression proximal to the fifth metacarpophalangeal joint | The shu-stream point and one of the eight confluent points; traditionally used for neck and back stiffness |
| SI-11 | Tianzong (天宗) | In the center of the scapular fossa, about one-third of the way from the lower border of the scapular spine | Traditionally used for shoulder and scapular tension |
| SI-19 | Tinggong (聽宮) | In the depression anterior to the tragus, with the mouth open | Classically associated with ear function |
Point locations follow the WHO Standard Acupuncture Nomenclature (1991). Gentle acupressure is generally considered low-risk; needling must only be performed by a licensed practitioner.
The 1–3 pm window
1–3 pm is the small intestine's peak. Traditional routines favor a light lunch and an easy walk rather than strenuous work in this window.
How this is viewed today
SI-3 is commonly included in trials of acupuncture for neck pain; reviews generally report short-term benefit with low certainty. Pressing points on the shoulder should be gentle, especially with a history of shoulder injury.
Sources & further reading
- Huangdi Neijing (黃帝內經), c. 2nd century BCE.
- Nanjing (難經), c. 1st–2nd century CE.
- World Health Organization, Standard Acupuncture Nomenclature, 2nd ed., 1991.
- Deadman P, Al-Khafaji M, Baker K. A Manual of Acupuncture. Journal of Chinese Medicine Publications.
- National Center for Complementary and Integrative Health, Acupuncture: What You Need To Know.
Related: Heart meridian · Bladder meridian · Body clock · all twelve meridians