男左女右。手中指第二节。屈指两纹尖相去为一寸。取稻秆心量。或薄篾量。皆易折而不伸缩为准。用绳则伸
缩不便。故不准。
\r中指定同身寸图\p05-c11a4.bmp\r
行针分寸中指传。屈指中节两纹尖。男左女右童稚一。长短肥瘦审经权。
法以中指第二节。屈指两纹尖。相去为一寸。童稚亦如之。虽人身有长短肥瘦不同。凡入针之分数。亦有不一。
而身形长者。其指节亦长身形短者。其指节亦短。但随其长短。以取分寸。则自准矣。肥人肌肉肥浓。血气充满。
宜刺三分半。瘦人肌肉瘦薄。血气未盛。宜刺二分。然虽如此。犹有经有权。不可执一而论。如遇不肥不瘦之人。
只在二三分之间。酌量取之。至于心领神会。又当存乎其人矣。
针灸原来宜坐向。理从四季顺自然。东南西北四维向。迎以生气本乎天。
四季人神所在处。禁针忌灸莫妄施。春在左胁秋在右。冬在腰间夏在脐。
四季人神所在之处。谓人之神气初动之处。同乎天地之流行也。禁针灸者。恐伤生气也。凡人神常在心。至春
在左胁者。肝主升也。秋在右者。肺主降也。冬在腰者。肾主藏也。夏在脐者。脾主化也。
一日足大（足之大指）二外踝。三日股内四在腰。五口六手七内踝。八腕九尻十背腰。十一鼻柱二发际。三牙
四胃五遍身。六胸七气（气冲也）八股内。九足二十内踝寻。二十一手小（手之小指）二外踝。三日肝足四手明。
（手阳明）五足（足阳明）六胸七在膝。八阴（男女前阴中也）九胫晦趺停。（足之十指岐骨也）
男性取左手，女性取右手。以手中指的第二节为基准，弯曲手指使中指第二节两端的横纹尖端相对，这两点之间的距离定为一寸。可以用稻草心的宽度来测量，或者用薄薄的竹篾来量，以容易折断且不伸缩变形为标准。如果使用绳子，因为绳子容易拉伸或收缩，所以不准确。
[图片：中指定同身寸图]
行针时确定分寸，通常参考中指。弯曲中指第二节的两个纹尖距离作为一寸的标准。对于儿童，无论男女，均按此标准；而对于成人，则需根据身高和胖瘦进行权衡调整。
方法是以中指第二节为准，弯曲手指时两纹尖的距离为一寸。儿童也采用同样的方法。虽然人的身体有长短、肥瘦的不同，但进针的深度分数也有差异。身形高大的人，其指节也较长；身形矮小的人，其指节也较短。只要随着其指节的长短来取分寸，自然就是准确的。
肥胖的人肌肉丰厚，气血充盈，适宜刺入三分半深；消瘦的人肌肉单薄，气血未盛，适宜刺入二分深。然而，即使如此，仍然需要懂得变通（经权），不能拘泥于一种说法。如果遇到不胖不瘦的人，只在二分到三分之间酌情选取。至于心中领会、神会意得，则取决于个人的悟性了。
针灸原本适宜采取坐姿，道理顺应四季的自然规律。东南西北及四维方位，迎着生气而行，这合乎天道。
四季中“人神”所在的部位，禁止针刺和艾灸，不要妄加施治。春季在左侧胁部，秋季在右侧，冬季在腰部，夏季在脐部。
所谓四季“人神”所在之处，是指人体神气初动的位置，与天地之气的流行相应。禁止针灸的原因是恐怕损伤生气。一般来说，“人神”常在心部，但到了春季在左胁，是因为肝主升发；秋季在右侧，是因为肺主肃降；冬季在腰部，是因为肾主闭藏；夏季在脐部，是因为脾主运化。
第一天在足大趾，第二天在外踝，第三天在大腿内侧，第四天在腰部，第五天和第六天在口部，第七天在内踝，第八天在手腕，第九天在尾骶骨，第十天在背部和腰部，第十一天在鼻梁，第十二天在发际，第十三天在牙齿，第十四天在胃脘，第十五天遍布全身，第十六天在胸部，第十七天在气冲穴，第十八天在大腿内侧，第十九天在足内踝，第二十天再次寻查足内踝。第二十一天在手小指，第二十二天在外踝，第二十三天在肝经足部，第二十四天在手阳明大肠经，第二十五天在足阳明胃经，第二十六天在胸部，第二十七天在膝盖，第二十八天在前阴（男女生殖器中间），第二十九天在小腿胫骨处，第三十天在足背十指的歧骨处。
For males, use the left hand; for females, use the right hand. Take the second phalanx of the middle finger. Bend the finger so that the tips of the two transverse creases at the ends of the second phalanx meet; the distance between these two points is defined as one *cun* (unit of measurement). One may measure using the core of a rice straw or a thin bamboo splint, provided it breaks easily and does not stretch or shrink. If a rope is used, it is inaccurate due to its tendency to stretch or contract.
[Image: Diagram of Middle Finger Standard *Cun* Measurement]
When needling, the degree of depth is determined by the middle finger. The distance between the two crease tips of the bent middle finger's second phalanx serves as one *cun*. For children, regardless of gender, this standard applies directly. For adults, adjustments must be made based on height and body constitution (flexibility vs. principle).
The method relies on the second phalanx of the middle finger: when bent, the distance between the two crease tips is one *cun*. Children follow the same method. Although human bodies vary in height and leanness or robustness, the depth of needle insertion also varies. Individuals with a tall stature have longer finger phalanges, while those with a short stature have shorter phalanges. By measuring the *cun* according to the length of their own finger phalanges, the measurement will naturally be accurate.
Individuals who are obese have thick muscles and abundant Qi and Blood; they are suitable for needle insertion to a depth of three-and-a-half *fen*. Individuals who are emaciated have thin muscles and less developed Qi and Blood; they are suitable for needle insertion to a depth of two *fen*. However, even in such cases, one must understand the principles of fixed rules versus flexible adaptation (*Jing* and *Quan*) and cannot adhere rigidly to a single rule. For individuals of average build, the depth should be酌情 selected between two and three *fen*. As for intuitive understanding and mental grasp, this depends on the practitioner's own insight.
Acupuncture and moxibustion originally suit a sitting posture, following the natural order of the four seasons. Facing the directions of East, South, West, North, and the four intermediate corners, one aligns with the vital Qi, which originates from Heaven.
In each season, there are specific locations where the "Human Spirit" resides; acupuncture and moxibustion are prohibited in these areas to avoid reckless application. In Spring, it is located in the left hypochondrium; in Autumn, in the right side; in Winter, in the waist; and in Summer, at the umbilicus.
The term "Human Spirit" refers to the location where the body's vital energy initially stirs, corresponding to the circulation of Heaven and Earth. Prohibiting acupuncture and moxibustion here is to prevent damaging the vital Qi. Generally, the Human Spirit resides in the Heart, but in Spring it moves to the left hypochondrium because the Liver governs ascending; in Autumn it moves to the right because the Lung governs descending; in Winter it moves to the waist because the Kidney governs storing; and in Summer it moves to the umbilicus because the Spleen governs transformation.
On the 1st day, it is at the big toe of the foot; on the 2nd day, at the lateral malleolus; on the 3rd day, inside the thigh; on the 4th day, in the waist; on the 5th and 6th days, at the mouth; on the 7th day, at the medial malleolus; on the 8th day, at the wrist; on the 9th day, at the sacrum/coccyx; on the 10th day, at the back and waist; on the 11th day, at the nasal bridge; on the 12th day, at the hairline; on the 13th day, at the teeth; on the 14th day, at the Stomach region; on the 15th day, throughout the entire body; on the 16th day, in the chest; on the 17th day, at Qichong (ST30); on the 18th day, inside the thigh; on the 19th day, at the medial malleolus of the foot; on the 20th day, again searching the medial malleolus. On the 21st day, at the little finger of the hand; on the 22nd day, at the lateral malleolus; on the 23rd day, at the Foot-Liver channel area; on the 24th day, at the Hand-Yangming (Large Intestine) channel; on the 25th day, at the Foot-Yangming (Stomach) channel; on the 26th day, in the chest; on the 27th day, at the knee; on the 28th day, at the external genitalia (middle of male and female genitals); on the 29th day, at the tibial shaft; on the 30th day, at the interosseous bones of the ten toes of the foot.