千金方云。尺寸之法。根据古者八寸为尺。仍取病者男左女右手中指上第一节为一寸。
亦有
长短不定者。即取手大拇指第一节横度为一寸。以意消息。巧拙在人。外台方亦同上法。又
一云。三寸者。尽一中指也。圣惠方云。今取男左女右手中指第二节。内度两横文相去为一
寸。自根据此法疗病多愈。今以此为定穴。取寸石藏用亦用圣惠方为准。以蜡纸条子。或薄篾
量患人男左女右中指中节。横文上下相去长短为一寸。谓之同身寸（若曲指节旁取背腹中
节上下两交角相去远近为一寸。若伸指即正取中指自上节下横文至中节中从上第二条横文长
者相去远近为一寸。与曲指一寸长短。亦相符合。然此人之身手指。或有异者。至于指文。
亦各不同。更在曲意详度之也）。此折纸与同身寸相等为六寸。逐寸以墨界之。勿令长短。
有所出入不同。截断收之。俟以此量灸穴自脊中第四椎下停分两旁各三寸。为膏肓 。足太
阳膀胱经脉气之所发也。
令患人用塾椅正坐。两足平蹋至地。膝与髀股高下俱平。两足相并。足指前齐。尽脱去
上身
衣服（若不尽脱。则衣袖束臂不能得脾骨相离。取穴不得。若气怯畏寒。则反着衣。以臂穿
袖。令领在胸前领下。以襟交覆腰间。候点定穴。灸时更穿袖令着背心以带束近穴处。勿令
与坐炷下火相碍）。曲脊伸臂。以两手按膝上。令中指当膝盖中。两大指紧相并。指头与膝
盖骨前齐。微用力直举。腕中。勿令斜屈动摇（段彦聪仲谋大夫云。石藏用谓以左手按右膝
右手按左膝。则胛骨开。尝试用其说。则两手相交。腕有高下。脾骨亦随之偏侧。当止如
旧法。以左手按左膝为是）。
《千金方》记载：定寸的方法，依据古法以八寸为一尺。同时取患者男性左手或女性右手的中间手指，其第一指节（近端指间关节处）的长度作为一寸。
也有手指长短不一的情况，此时则取手大拇指第一指节的宽度横向测量作为一寸。这需要用心斟酌，技巧的高低在于人。
《外台秘要》也采用同样的方法。
另一种说法是：三寸的长度，即整个中间手指的长度。
《太平圣惠方》记载：现在取男性左手或女性右手中间手指的第二指节（中节），内侧两条横纹之间的距离作为一寸。根据这种方法治疗疾病大多痊愈，现在将其定为取穴的标准尺寸。石藏用也采用《圣惠方》作为准则。
用蜡纸条或薄竹片，量取患者男性左手或女性右手中间手指第二指节，上下横纹之间的距离长短作为一寸。这称为“同身寸”（如果弯曲手指关节旁侧取背腹中节上下两个交角之间的距离作为一寸；如果伸直手指，则正取中指从第一节下方的横纹到第二节中间从上数第二条横纹的较长者，其距离作为一寸。这与弯曲手指量出的一寸长短也是相符的。然而人的身体手指，有的存在差异，至于指头的纹路，也各不相同，更需曲意详细揣度）。
将这张折纸与同身寸相等的长度定为六寸，逐寸用墨线标记界限，不要让长短有所出入不同。截断后收好，等待用它来量取灸穴。
自脊中第四椎下停分两旁各三寸处，为膏肓穴，这是足太阳膀胱经经脉气机所发出的部位。
让患者坐在靠背椅上端正坐好，两脚平踏至地面，膝盖与大腿的高度一致，两脚并拢，脚趾前端齐平。完全脱去上身衣服（如果不能完全脱去，则衣袖束住手臂会导致肩胛骨无法分开，取穴就不准确。如果气弱怕冷，则重新穿上衣服，将手臂穿过袖子，使领口在胸前领下，衣襟交叉覆盖腰间，等点定穴位后，艾灸时再穿上背心，用带子束紧靠近穴位处，不要让它与坐着的艾炷下的火焰相妨碍）。
弯曲脊柱，伸展手臂，用两手按住膝盖上，使中指对准膝盖正中，两大拇指紧紧相并，指头与膝盖骨前缘齐平。微微用力向上直举，手腕中间部分，不要让手腕斜屈动摇。（段彦聪仲谋大夫说：石藏用认为用左手按右膝、右手按左膝，则肩胛骨会打开。尝试使用他的说法，则两手相交，手腕会有高低不平，肩胛骨也会随之偏侧。应当停止像那样做，还是按照旧法，用左手按左膝为好。）
The *Qianjin Fang* (Prescriptions Worth a Thousand Gold) states: The method of measuring *cun* (units of measurement) is based on the ancient standard where eight *cun* equal one chi. It also takes the first phalanx (proximal interphalangeal joint area) of the middle finger of the patient's left hand (for males) or right hand (for females) as one *cun*.
There are cases where finger lengths vary. In such instances, the transverse width of the first phalanx of the thumb is taken as one *cun*. This requires careful consideration; the skill lies with the practitioner.
The *Waitai Miyao* (Essential Prescriptions from the Imperial Cabinet) also adopts this same method.
Another saying is: Three *cun* corresponds to the length of the entire middle finger.
The *Taiping Shenghui Fang* (Holy and Beneficent Prescriptions of the Taiping Era) states: Currently, the distance between the two inner transverse creases of the second phalanx (middle segment) of the middle finger of the patient's left hand (for males) or right hand (for females) is taken as one *cun*. Diseases treated according to this method have mostly healed, so it is now established as the standard for locating acupoints. Shi Cangyong also uses the *Shenghui Fang* as the criterion.
Using a strip of wax paper or thin bamboo sliver, measure the distance between the upper and lower transverse creases of the middle segment of the middle finger of the patient's left hand (for males) or right hand (for females) as one *cun*. This is called "Tongshen Cun" (Body Inch). (If measuring along the side of the flexed finger joint, the distance between the upper and lower angles of the middle segment on the dorsal and ventral sides is taken as one *cun*; if extending the finger, the longer distance from the transverse crease below the first phalanx to the second transverse crease from the top on the middle segment is taken as one *cun*. This matches the length obtained by flexing the finger. However, fingers may vary among individuals, and fingerprint patterns also differ; thus, careful deliberation is required.)
This folded paper, equal in length to the Tongshen Cun, is set at six *cun*. Each *cun* is marked with ink lines, ensuring no variation in length. Cut off and store it for use in measuring moxibustion points.
Three *cun* lateral to the midpoint below the fourth thoracic vertebra on the spine is the Gao Huang (BL 43) point, which is where the Qi of the Foot-Taiyang Bladder Meridian emerges.
Instruct the patient to sit upright on a chair with back support, placing both feet flat on the ground, with knees and thighs at the same height, legs together, and toes aligned. Remove all upper body clothing completely. (If not fully removed, sleeves binding the arms will prevent the scapulae from separating, making accurate point location impossible. If the patient has weak Qi and fears cold, they may put clothes back on, inserting arms into sleeves, keeping the collar under the chest and lapels crossed over the waist. After marking the points, during moxibustion, wear a vest and tie it tightly near the acupoint to avoid interference with the flame of the seated moxa cone.)
Flex the spine and extend the arms, pressing both hands onto the knees so that the middle fingers align with the center of the kneecaps, with the thumbs pressed closely together, their tips level with the anterior edge of the patella. Apply slight upward force to lift straight, keeping the wrists neutral without tilting, bending, or shaking. (Duan Yancong Zhongmou Daifu stated: Shi Cangyong believed that pressing the left hand on the right knee and the right hand on the left knee would open the scapulae. Attempting this method resulted in crossed hands with uneven wrists and tilted scapulae. One should stop doing this and adhere to the old method: pressing the left hand on the left knee is correct.)