Acupuncture Point SJ-4: Yangchi (陽池, Yang Pool)

Location Guides:

Classifications:

Yuan-Source point
Binding point of the hand Shaoyang Sinews

Location:

On the dorsum of the wrist, at the level of the wrist joint, in the depression between the tendons of extensor digitorum communis and extensor digiti minimi.

Needling:

Slightly oblique proximal insertion 0.3 - 0.5 cun, or transverse insertion towards the radial side of the wrist beneath the tendons 0.5 - 1 cun.

Classical Needling:

"The Shaoyang usually has little Blood and much Qi" (Su Wen 素問 ch. 24) implying this channel should normally be needled.
"The hand Yin and Yang receive their Qi via nearby paths so their Qi arrive swiftly. The depth of piercing must not exceed 2 fen and must not remain inserted for longer than one exhalation" (Ling Shu 靈樞 ch. 12).
"It is needled to a depth of two fen, (the needle) is retained for a duration of six exhalations, and it is moxaed with three cones" (Huangfu Mi 皇甫謐, 3rd Century, Zhenjiu Jiayi Jing 針灸甲乙經).

TCM Actions:

Relaxes the sinews and alleviates pain
Clears Heat

TCM Indications:

Swelling and pain of the neck, pain of the shoulder and arm, weakness and pain of the wrist, redness and swelling of the wrist.
Deafness, Throat Painful Obstruction (喉痹, Hou Bi).
Wasting and thirsting disorder, Malarial (瘧, Nue) Disorders, febrile disease with absence of sweating.
Dry mouth with agitation and oppression, Heart pain with fullness of the chest.

Neuroanatomy:

Superficial Innervation: Ulnar nerve from C8 and T1

Dermatome Segment: C7, C8

Martial Applications & Effects of Injury:

See Montaigue, Dim Mak Locations, Taijiworld.com for explanation of effects.

Major Combinations:

Contraction of the elbows with tightness of the sinews of the hands resulting in inability to open the hands:
Yangchi SJ-4 with Zhongzhu SJ-3, Quchi LI-11, Hegu LI-4 and Chize Lu-5
(Yang Jizhou, 杨继洲, 1601: Zhen Jiu Da Cheng, 針灸大成, Great Compendium of Acupuncture and Moxibustion).
Problems relating to the Sixth Level of Manifestation of the Soul, equivalent to the Ajna Chakra:
Yangchi SJ-4 with Yingu Kid-10 and Waiguan SJ-5
(Yuen, 2005, 3 Spirits & 7 Souls, see notes below).

I Ching Hexagram:

䷈ Xiao Xu 小畜 Gentle Cultivation.

Trigrams: Qian (Heaven) below, Xun (Wind) above.

Strength within, gentle penetration without — the powerful impulse to act is restrained by a soft, persistent influence. This is the small taming the great.

Nuclear trigrams: Lines 2-3-4 form Dui (Lake). Lines 3-4-5 form Li (Fire). Beneath the taming, there is openness and joy (Dui) and clarity (Li). The hidden message: the restraint is not oppressive. It is gentle, clear, and ultimately joyful.

Judgement:
小畜：亨。密雲不雨，自我西郊。
The Taming Power of the Small. Success. Dense clouds, no rain. From our western region.

The small is taming the great. This is a time of restraint, not action. The clouds are gathering, but the rain has not come. Do not force the issue. The small influence is real, but it is not yet strong enough to bring completion. Wait.

Lines:

Line	Yin/Yang	Image	Literal Translation	Commentary
1	Yang	復自道，何其咎，吉	Returning by one's own path. What trouble? Gain.	Yang at the bottom. The creative force is strong but it returns to its own way. It does not need to be tamed yet. The path is correct. Gain because the return is natural and unforced.
2	Yang	牵復，吉	Drawn back. Gain.	Yang at 2, central and correct. The yin at 4 draws it back. It goes willingly. This is the beginning of the taming — the strong allows itself to be restrained by the small. Gain because the restraint is accepted, not resisted.
3	Yang	舆說輻，夫妻反目	The carriage loses its spokes. Husband and wife look at each other with anger.	The threshold. The restraint has become too tight. The carriage cannot move. The relationship breaks down. This is the crisis of the taming — when restraint becomes oppression.
4	Yin	有孚，血去惕出，無咎	There is sincerity. Blood departs, fear exits. No trouble.	The ruler line. Yin at 4. The taming is sincere and gentle. The danger passes. The small influence is correct and therefore blameless. No trouble because the restraint is applied with sincerity.
5	Yang	有孚攣如，富以其鄰	There is sincerity, drawing together. Wealth shared with neighbours.	Yang at 5, central and correct. The strong and the small are now in harmony. The wealth of the strong is shared with those around him. This is the success of the taming — not domination, but mutual benefit.
6	Yang	既雨既處，尚德載，婦貸厲，月幾望，君子征凶	Already rain, already settled. Virtue is honoured and carried. The woman's perseverance is Dangerous. The moon is nearly full. The gentleman's campaign brings Loss.	Yang at the top. The rain has finally fallen. The taming is complete. But the yin has now become too strong — the moon is full, and the woman (yin) is dangerously powerful. The gentleman should not act. Loss because the time for action has passed.

Image:
風行天上，小畜。君子以懿文德。
Wind moving above heaven: Xiao Xu. Thus the gentleman perfects his literary virtue..

The wind blows across the sky — gentle, persistent, shaping the clouds but not disrupting them. The gentleman perfects his literary virtue (懿文德, yi wen de). He cultivates the small, refined qualities — culture, manners, eloquence, grace — that gently influence others without force. This is the taming power of the small: not coercion, but cultivation.

Acupuncture Point Connections:

Shared with Neiguan Pc-6.
Inverted into ䷉ (Feishu Bl-13 or Dachangshu Bl-25).
Balanced by ䷏ (Taichong Liv-3 or Guangming GB-37).

Hexagram attributions are my own with an explanation given in the glossary.

Notes:

Moxa at this point moves yuan qi through the spine, opening the entire Triple Heater mechanism to remove blocks in the channels that prevent back shu and source points points working (Yuen, 2005, The Extraordinary Vessels). Also see Zusanli St-36 and Quchi LI-11 for a similar application when the channels stop working from exhaustion.

When combined with Waiguan SJ-5 and Yingu Kid-10 this point relates to the Sixth Level of Manifestation of the Soul or the Ajna chakra concerned with the Realm of Immortality and the Will to Create endless possibilities. It asks what we would create if we were to live forever? This point pools the Yang, Yingu Kid-10 pools the Yin and Waiguan SJ-5 emanates the resulting mixture outwards via the Yang wei mai and the San jiao as an irrigation system.
This stage also relates to the formation of the spiritual embryo and attainment of immortality in meditation practice (Yuen, 2005, 3 Spirits & 7 Souls).

In Sufism this level would relate to the Valley of Bewilderment described by Attar in the Conference of the Birds as:

"Behold! The next is the valley of bewilderment
Here pain and regret ever rave and thunder;
When the pilgrim in this vortex descends
He loses the path in amazement and awe;
He will say 'I know nothing of such riddle,
I know not this or that, I'm blank in
the middle' ..."

Here the mystic awakens to a new reality that is both wonderful and bewildering and is filled with pain and discontent as their previous sense of worldly identity collapses.

Like the other even (Yin) sets there is one point representing Yang (Yangchi SJ-4), one representing Yin (Yingu Kid-10) and one that unifies them (Waiguan SJ-5).

In Thai massage:
Point along the outer Kalatharee sen line where the channel splits into five lines going to the fingers.
Indicated for carpal tunnel and wrist pain (Salguero & Roylance, 2011, Encyclopedia of Thai Massage)

Reference Notes:

Basic information on location, needle depth, TCM actions, indications and combinations is taken from Deadman et al (2001): A Manual of Acupuncture with additional anatomical information researched by reference to Gray's Anatomy (38th Ed., 1995) unless otherwise referenced. Images were found on acupunctureschoolonline.com and can be traced back to Claudia Focks (2008) Atlas of Acupuncture originally. I cannot claim any credit or rights over them. Other sources should be quoted in the text.

For some of the more unusual terms I have created a glossary here

陽 池  : Yangchi : Yang Pool

SJ-4 : Hand Shaoyang San Jiao 4