大都 : Dadu : Great Metropolis

Location Guides:

Classifications:

Ying-Spring and Fire point
Mother point of the Spleen channel

Location:

On the medial side of the big toe, in the depression distal and inferior to the first metatarso-phalangeal joint.

Needling:

Oblique inferior insertion 0.3 - 0.5 cun

Classical Needling:

"The Taiyin usually has much Qi and little Blood" (Su Wen 素問 ch. 24) implying this channel should normally be needled.
"The foot Taiyin is to be pierced 3 fen deep and remain inserted for four exhalations" (Ling Shu 靈樞 ch. 12).
"It is needled to a depth of threefen, (the needle) is retained for a duration of seven 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:

Regulates the Spleen
Resolves Dampness and Damp-heat
Harmonises the Middle Jiao and clears Heat

TCM Indications:

• Sudden swelling of the four limbs, heaviness of the body with pain of the bones, swelling of the limbs, oppression of the chest.
  
• Abdominal distension, epigastric pain, vomiting, diarrhoea, constipation, agitation when hungry and dizziness when full, Sudden Turmoil (霍亂, Huo Luan) Disorder.
  
• Agitation, insomnia, Heart pain, febrile disease with absence of sweating, febrile disease that does not disperse, injury by cold leading to hands and feet counterflow cold, Visual Dizziness.
  
• Lumbar pain with inability to turn, disorders of the big toe, heat sensation in the soles of the feet.

I Ching Hexagram:

䷕ Bi 賁 Grace, luminosity

Shared with Jiexi St-41. Balanced by ䷮ (Chize Lu-5 or Erjian LI-2).

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

Neuroanatomy:

Superficial Innervation: Superficial peroneal nerve from L4 - S1

Dermatome Segment: L4

Martial Applications & Effects of Injury:

Striking this point will weaken the Spleen and slow the flow is Qi in the channel, causing a lack of power, nausea with vomiting and a loss of memory in the long term if untreated. It will also have an affect upon communication between Heaven and Earth leading to greater vulnerability to shock. It may be grabbed and squeezed violently while grappling to cause an attacker to let go (Montaigue, Dim Mak Locations, Taijiworld.com).

Major Combinations:

• Heat disease accompanied with spontaneous sweating which is in accordance with the norms and further sweating is indicated:
    Dadu Sp-2, Taiyuan Lu-9, Yuji Lu-10 and Taibai Sp-3. Draining these points makes the Heat disappear, supplementation here makes a sweat emit. If sweating is extreme then Sanyinjiao Sp-6 ends it
    (Anon, 400BC-260AD: Huang Di Nei Jing Ling Shu, 黃帝內經靈樞, Yellow Emperor's Inner Classic: Spiritual Pivot, Ch. 23, On Heat Diseases).
  
  
• Severe Heart pain accompanied by distended abdomen and fullness in the chest, associated with the Stomach:
    Dadu Sp-2 and Taibai Sp-3
    (Anon, 400BC-260AD: Huang Di Nei Jing Ling Shu, 黃帝內經靈樞, Yellow Emperor's Inner Classic: Spiritual Pivot, Ch. 24, On Counterflow Diseases).
  
  
• Vomiting:
    Dadu Sp-2 with Chengguang Bl-6
    (Wang Zhizhong, 王執中, 1220: Zhen Jiu Zi Sheng Jing, 針灸資生經, Classic of Supporting Life with Acupuncture and Moxibustion).
  
  
• Febrile disease with absence of sweating:
    Dadu Sp-2 with Jinggu Lu-8
    (Gao Wu, 高武, 1529: Bai Zheng Fu, 百症賦, Ode of a Hundred Symptoms)
  
  
• Stagnation of Qi, lumbar pain with inability to stand:
    Dadu Sp-2 with Henggu Kid-11
    (Xi-Hong Fu, 席弘賦, Ode of Xi-Hong. First recorded in: Xu Feng, 徐鳳, 1439: Zhen Jiu Da Quan, 針灸大全, Complete Collection of Acupuncture and Moxibustion).

Notes:

In five element acupuncture this point is reinforced to tonify Spleen deficiencies.

Ling Shu Ch. 6 suggests piercing the Ying points (and Shu points according to Unschuld, 2016, but not according to Wu & Wu, 201) of the Yin channels if a disease is in the Yin of the Yin realm (e.g. the Zang organs) suggesting this point (and Taibai Sp-3) in diseases of the Spleen.

Ling Shu Ch. 9, On Ends and Beginnings, advises that in the case of Heat associated with receding Yin Qi the Yang conduit should be pierced once and the Yin conduits twice. Based on other recommendation to use the He-Sea of the Yang conduits (Ch. 19) and the Yuan-Source with the Ying-Spring points (Chs. 6, 19 and 24) to clear Heat from the Zangfu, that would suggest this point, Taibai Sp-3 and Zusanli St-36 as a protocol to clear Heat in the Stomach/Spleen. Next it advises that in Cold associated with receding Yang Qi the Yang should be pierced twice and the Yin once but no such obvious protocol is evident for this situation. Another interpretation that would match with common practice today, based on the idea of odd numbers being Yang/moving/clearing while even numbers are Yin/tonifying/reinforcing, is that the points on the channel to be cleared are pierced on one side only while those on the channel to be tonified are pierced bilaterally.

Ling Shu Ch. 19, on the Four Seasonal Qi, advises selecting the Jing-Well and Ying-Spring openings in winter, piercing deeply and retaining for a while. However, the character for "retain" 留 is a combination of 田 "a field," possibly referring to the idea of waiting for things to grow, and 卯 which is the 4^th Earthly Branch (Mao, Rabbit, ䷡, 5-7 am, Large Intestine) and said to derive from a Shang Dynasty glyph, originally referring to a blood sacrifice (a person or animal cut in half) before coming to mean bloodletting and "pouring out" (Smith, 2011). This might suggest it was actually referring to bleeding these points, and maybe even letting the points bleed for a time rather than retaining the needle.

Ling Shu Ch. 44, On the Qi Moving in Accordance with the Norms, indicates that the Ying-Spring points should be pierced in spring or when the disease is associated with a change in complexion. The seasonal aspect should not be interpreted literally as it describes the colours as "controlled by spring". It also describes the morning, afternoon, evening and night cycle of the day to be like the four seasons of the year with morning corresponding to spring.

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