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Regarding the methods for measuring and determining acupuncture points using proportional inches, there are various opinions. Those who exclusively advocate the "body-inch" (Tongshen Cun, a measurement unit based on the patient's own body parts) without relying on the *Ling Shu: Bone Proportions* chapter often result in inconsistencies. The location of an acupoint corresponds to the separation of muscle fibers, joint gaps, or depressions between bones. Therefore, it is said that one can feel the arterial pulse at these spots, or find them in concave areas, or within depressions. Thus, by seeking out these concave or depressed areas and palpating for the arterial pulse, one can locate the acupoints without strictly adhering to fixed measurements, which is self-evident. Although ancient texts occasionally mention specific measurements, they were generally descriptive and should not be rigidly applied.

Furthermore, the term "body-inch" (Tongshen Cun) does not appear in ancient books. It was also known as the "finger-inch," first appearing in the teachings of Sun Simiao (Sun Zhenren). This method uses the patient's own fingers to measure their own body, hence the name "same" (Tong). It does not refer to the physician using their own fingers to measure the patient. Wang Bing (Wang Taipu), in his commentary on the *Su Wen*, labeled each acupoint with "X body-inches." Later generations abandoned the *Bone Proportions* chapter and adopted the body-inch method. The *Mingtang Jiu Jing* cites Bian Que regarding the body-inch, and many medical texts falsely attribute their foundations to Bian Que, though its origin remains unclear.

Examining the character "cun" (inch), it originates from the Cun Kou pulse position. Its structure implies spreading fingers to diagnose the pulse, indicating that the human body specifically designates the Cun Kou area as one cun. Additionally, the *Kongzi Jiayu* states "spreading fingers reveals the cun," and the *Gongyang Zhuan* mentions "skin-cun meeting," with annotations explaining that "side-hand is skin." All these references indicate that spreading fingers constitutes a cun, not measuring the distance between two creases on a finger. For instance, if one measures the distance between the nipples as 9.5 cun and uses fingers to gauge it, one finger width equals one cun. This illustrates that the meaning of "spreading fingers" is not about rigidly fixing dimensions when locating points. For areas lacking bony landmarks for reference, one should rely on the proportions from the *Bone Proportions* chapter to measure, ensuring that individuals of different fatness, thinness, height, and shortness are correctly assessed. In cases of sudden emergency, one may use one's own hand to measure the patient's body, adjusting mentally according to the patient's build. For example, from Jiwei (CV15) to Qizhong (CV12), eight finger widths might fit; thus, one finger width equals one cun. Four finger widths would locate Zhongwan (CV12), and three finger widths Shangwan (CV13). If only seven finger widths fit, then one finger width is slightly less than one cun. This approach minimizes error. Other body-inch methods may not always be applicable.

Recently, three men met. One was five chi six cun tall; measuring his body-inch with a carpenter's ruler yielded 0.75 cun. Another was five chi three cun tall, yielding 0.8 cun. The third was five chi tall, yielding 0.75 cun. Furthermore, taking one cun from the mouth/eyes or extrapolating rib/chest measurements from the eight-cun nipple distance is highly unfounded and absurd, and should not be followed.

Cui Zhiti stated: The size of all acupoints varies with the person's physique. One must measure the center of the two creases on the middle segment of the middle finger of the left hand for men or the right hand for women as one cun. He also stated that all acupoints follow the individual's size, taking the first segment of the middle finger as one cun (*Qianjin Yifang* omits this phrase). Another view holds that three cun equals the length of one entire middle finger. These two views share the same meaning.

Xu Feng stated: When the thumb and middle finger are bent into a ring, the distance between the upper and lower edges of the transverse crease on the middle segment of the middle finger is taken as one cun, called the body-inch method. Yang Jizhou stated: The distance between the heads of the transverse creases on the inner side of the second segment of the middle finger is one cun. Rice straw cores or thin bamboo strips can be used for measurement because they break easily and do not stretch, serving as a standard. Rope is unsuitable due to its elasticity. Later generations mostly followed this saying.

Sun Simiao stated: Acupoints on the body are where zang-fu organs, Ying-Wei (nutritive and defensive qi), blood vessels circulate, and interior-exterior relationships interact, each governing specific functions. In emergencies, careful examination is required. People vary in age, stature, and body composition (fat/thin). Precise thought and discussion are necessary to determine accurate measurements; one cannot apply a uniform standard to avoid errors. The measurement method is based on the ancient standard of eight cun equaling one chi. Following the rule of left hand for men and right hand for women, the first segment of the middle finger is one cun. If the finger length is irregular, the first segment of the thumb, measured horizontally, is taken as one cun, adjusted by judgment. He further stated: Rely on muscle textures, joint gaps, concave depressions, and areas where pressure brings relief to the patient. Only through careful, calm, and attentive practice can one locate them accurately. This view is most appropriate, and our school adopts it as the standard. Some people mistakenly interpret "horizontally measuring the thumb's first segment crease" as measuring the distance between the two horizontal creases of the thumb as one cun, which contradicts Sun's intent. "Horizontal" refers to the upright posture of the body, and similarly for fingers, as seen in descriptions of points like Taiyuan (LU9), Daling (PC7), and Quze (PC3) which mention "transverse creases."

The *Qianjin Fang* adds: Comparing the ancient chi to the current chi yields 0.8. Since our country's carpenter's ruler is identical to the Tang chi, 0.8 refers to 0.8 units on the current carpenter's ruler. By gently following the finger and measuring the transverse crease horizontally, one gets one carpenter's cun; measuring the first segment horizontally yields 0.8 cun. This indicates that the width of the finger corresponds to the meaning of "spreading fingers." Moreover, the *Qianjin Fang* did not mention the crease but rather the horizontal span of the first segment.

The *Zhou Hou Bei Ji Fang* states: Using the patient's hand to horizontally cover and hold four fingers together is named "Yifu" (one adult/man). "Fu" is written as "Fu" in *Jiayu* and "Fu" in *Gongyang*, likely due to phonetic similarity. The *Qianjin Fang* states: To measure one Yifu, place the hand palm down, extend four fingers, align them against the middle segments of the four fingers, and the horizontal span across them constitutes one Yifu. There are two types of Yifu: some use three fingers, while others use four fingers for treating weak legs via moxibustion, following Zhi Facun's old method.

The *Waitai Miyao Fang* states: According to the *Mingtang* system, standing is the correct posture for measurement. If there are variations in length, point location will be inaccurate. Qin Chengzu and Hua Tuo also stated that three or four fingers serve as the standard. For example, taking Sanyangjiao (ST36) with four fingers, if each finger is 0.6 cun wide, four times six is twenty-four, totaling 2.4 cun wide. How can such a broad measurement accurately locate the point? Taking Huangdi as the root, these diverse theories are unreliable. Currently, regarding the eight methods for treating beriberi, the points above and below Sanyangjiao (ST36) are cited. From the *Zhou Hou Bei Ji Fang* onwards, many texts use the Yifu method, leading to inconsistent point locations. Therefore, the Yifu method is rejected. These various theories are recorded here for reference.