甲乙经云、自大椎下至尾 骨二十一椎。长三尺。折量取俞穴。或云、第一椎上更有大
椎。
在宛宛陷中。非有骨也。有骨处即是第一椎。若以大椎至尾 二十一椎长三尺法校之。则上
节云椎每倾一寸四分。惟第七椎下至于膂骨多分之七。故上七节共九寸八分分之七。下节十
四椎。每椎一寸四分分之五有奇。故下七节共二尺一分分之三。此亦是一说也。但第一椎有
骨。乃骨节之收。大椎虽无骨。实是穴名。既曰自大椎下至十一椎。岂可不量大椎以下。或
者之说。于是不通矣。
自蔽骨下至脐八寸。而中管居其中。（上下各四寸。）气穴论注云、中管居心蔽骨与脐之
中。是也。按明堂下经云、鸠尾在臆前蔽骨下五分。人无蔽骨者。从岐骨际下行一寸。则是欲定
中管之中。又当详有蔽骨无蔽骨也。（当准人长短肥瘠量。）自脐下寸半为气海。三寸为丹田
。至屈骨凡五寸。千金云、屈骨在脐下五寸明堂下经亦云、屈骨在横骨上中极下一寸。当准
铜人云、幽门夹巨阙旁各五分。肓俞夹脐各五分。（明堂云。在巨阙旁各寸半通谷夹上
管旁相去三寸。）不容在幽门旁各寸半。天枢去肓俞寸半夹脐。期门在不容旁寸半。大横直脐旁
。（不容天枢期门既各寸半，则幽门肓俞各五分误矣。）铜人云、肾俞在十四椎下两旁各寸
半。与脐平。肓门在十三椎下相去各三寸。与鸠尾相直。肾俞既与脐平。肓门乃与鸠尾相直
甲乙经云、人有长七尺五寸者。发以下至颐一尺。结喉至 （鸠尾也。）一尺三寸。
至
廉至内踝一尺三寸。内踝至地三寸。又膝 至跗属一尺六寸。跗属至地三寸。又肩至肘一尺
七寸。肘至腕一尺二寸半。腕至中指本节四寸。本节至末四寸半。
《甲乙经》记载：从大椎穴向下至尾骨共二十一椎。全长三尺。通过折量法来取俞穴。有人说，在第一椎之上还有大椎穴。它位于宛宛凹陷之中，此处并没有骨头。有骨头的地方才是第一椎。如果用“自大椎至尾骨二十一椎长三尺”的方法来校勘，那么上节记载的每椎倾斜一寸四分，只有第七椎以下至膂骨多出了七分之二。所以上七节总共九寸八分又三分之二；下节十四椎，每椎一寸四分又五分之一有余，所以下七节总共二尺一分又三分之一。这也是其中一种说法。但是第一椎是有骨的，那是骨节的收束处。大椎虽然无骨，但确实是穴位名称。既然说“自大椎下至十一椎”，怎么能不测量大椎以下的距离呢？或许这种说法不通顺。
从蔽骨（剑突）下至脐部八寸，而中管穴居于其中。（上下各四寸。）《气穴论》注解说：中管穴位于心蔽骨与脐之间。这是正确的。按《明堂下经》记载：鸠尾穴在臆前蔽骨下五分。如果人没有蔽骨，就从岐骨际下行一寸。这样想要确定中管穴的位置，又应当详细辨别是否有蔽骨。（应当根据人的高矮胖瘦来衡量。）从脐下寸半为气海穴。三寸为丹田穴。至屈骨凡五寸。《千金方》记载：屈骨在脐下五寸。《明堂下经》也说：屈骨在横骨上中极下一寸。应当参照铜人图：幽门穴夹巨阙旁各五分。肓俞穴夹脐各五分。（《明堂》记载：在巨阙旁各寸半。通谷穴夹上管旁相去三寸。）不容穴在幽门旁各寸半。天枢穴去肓俞穴寸半夹脐。期门穴在不容旁寸半。大横穴直对脐旁。（既然不容、天枢、期门各相距寸半，那么幽门、肓俞各五分就错了。）铜人图记载：肾俞穴在十四椎下两旁各寸半。与脐平齐。肓门穴在十三椎下相去各三寸。与鸠尾穴相直。肾俞既与脐平齐，肓门乃与鸠尾相直。
《甲乙经》记载：人有身高七尺五寸的，头发以下至颐部一尺。结喉至鸠尾穴一尺三寸。至廉泉穴至内踝一尺三寸。内踝至地三寸。又膝至跗属一尺六寸。跗属至地三寸。又肩至肘一尺七寸。肘至腕一尺二寸半。腕至中指本节四寸。本节至末四寸半。
The *Jia Yi Jing* (Systematic Classic of Acupuncture and Moxibustion) states: From the Dazhui (GV14) acupoint downward to the coccyx, there are twenty-one vertebrae. The total length is three chi. Shuxue points are located by folding measurement. Some say that above the first vertebra, there is another Dazhui point. It is located in a concave depression where there is no bone. The place with bone is indeed the first vertebra. If we verify using the method that "from Dazhui to the coccyx, twenty-one vertebrae measure three chi," then the upper section records that each vertebra inclines 1.4 cun, but from the seventh vertebra down to the spinous process of the lumbar region, it exceeds by 2/7ths of a fen. Thus, the upper seven segments total 9.8 + 2/7 fen; the lower fourteen vertebrae, each measuring 1.4 + 1/5 cun or more, mean the lower seven segments total 2 chi 1 + 3/7 fen. This is also one interpretation. However, the first vertebra has bone, which is the convergence of the vertebral joints. Although Dazhui lacks bone, it is truly an acupoint name. Since it says "from Dazhui down to the eleventh vertebra," how can one fail to measure below Dazhui? Perhaps this explanation is inconsistent.
From below the xiphoid process (Bigu) to the umbilicus is eight cun, and Zhongwan (CV12) resides in the middle (four cun above and four cun below). The commentary on the *Qi Xue Lun* (Treatise on Qi Points) states: Zhongwan is located between the heart's xiphoid process and the umbilicus. This is correct. According to the *Ming Tang Xia Jing* (Lower Classic of Ming Tang): Jiwei (CV15) is five fen below the anterior xiphoid process. If a person lacks a xiphoid process, measure one cun downward from the junction of the costal cartilages. To determine the center of Zhongwan, one must carefully examine whether a xiphoid process exists. (Measurement should be adjusted according to the individual's height and body composition.) One and a half cun below the umbilicus is Qihai (CV6). Three cun below is Dantian. Up to the flexed bone (qugu), it is five cun. The *Qian Jin Fang* (Essential Prescriptions Worth a Thousand Gold) states: The qugu is five cun below the umbilicus. The *Ming Tang Xia Jing* also states: The qugu is one cun below Zhongji (CV3) on the Henggu. One should refer to the Bronze Man model: Youmen (ST21) is five fen lateral to Juque (CV14). Huangshu (SP16) is five fen lateral to the umbilicus. (*Ming Tang* states: [Youmen] is 1.5 cun lateral to Juque. Tonggu is three cun apart laterally to Shangguan.) Burong (ST19) is 1.5 cun lateral to Youmen. Tianshu (ST25) is 1.5 cun lateral to Huangshu, adjacent to the umbilicus. Qimen (LR14) is 1.5 cun lateral to Burong. Daheng (SP15) is directly lateral to the umbilicus. (Since Burong, Tianshu, and Qimen are each 1.5 cun apart, the claim that Youmen and Huangshu are five fen apart is erroneous.) The Bronze Man model states: Shenshu (BL23) is 1.5 cun bilateral to the fourth lumbar vertebra (below the 14th thoracic vertebra counting from cervical), level with the umbilicus. Huangmen (BL63) is three cun apart below the thirteenth thoracic vertebra, aligned vertically with Jiwei. Since Shenshu is level with the umbilicus, Huangmen aligns vertically with Jiwei.
The *Jia Yi Jing* states: For a person who is seven chi five cun tall: from the hairline to the chin is one chi. From the laryngeal prominence to Jiwei (CV15) is 1.3 chi. From Lianquan (CV23) to the medial malleolus is 1.3 chi. From the medial malleolus to the ground is three cun. From the knee joint to the tarsal connection is 1.6 chi. From the tarsal connection to the ground is three cun. From the shoulder to the elbow is 1.7 chi. From the elbow to the wrist is 1.25 chi. From the wrist to the proximal phalanx base of the middle finger is four cun. From the base to the tip is 4.5 cun.