经言肝主身之筋膜。脾主身之肌肉。肉之大会为谷。肉之小会为 。分肉之间。 谷之会。以行营卫。以会
大气。圣人于此。不啻三致意焉。且脾胃属土。其充在肌。故观肌肉之消长。可知脾胃之盛衰。夫脾者。孤脏
以灌四旁者也。胃者。五脏六腑所禀气者也。诊脉虽以胃气为本。观形当以肌肉为先也。若夫形肉已脱。
九候虽调。圣人不曰可生。而曰犹死。则是肌肉之消长。尤关胃气之有无矣。诊之之法。其可不讲乎。析而
言之。如形充而大肉 坚而有分者肉坚。肉坚则寿矣。形充而大肉无分理不坚者肉脆。肉脆则夭矣。肥
而泽者。血气有余。肥而不泽者。血有余。气不足。瘦而无泽者。血气不足。瘦而泽者。血不足。气有余。肥者耐
寒。瘦者耐热。肉瘦削者脾虚。肉壅肿者脾实。肉蠕动者脾病热。肉 者脾中风。筋惕肉 者阳虚。食减
肉消者意损。瘦削干黑者。肉极之证。肉宛 弱者。肉痿之征。肉上粟起者。寒客皮肤。肌肤不仁者。邪入络
脉。肌肉充盛者。形气有余。肌肉消减者。形气不足。肥人肉如棉絮者。谓之无气。妇人肌若鱼鳞者。谓之带
下。骨痛肉枯者。寒胜其热。烂肉腐肌者。热胜其寒。疳病形容羸瘦者。症起肠胃之内。瘅疟肌肉消烁者。邪
舍分肉之间。脱肉者死。破 者死。大肉陷下。大骨枯槁者皆死。肌肉不滑泽。肉满唇反者。肉先死。疠风割
切不痛者。肉先死。肉痿软。唇反。人中满者。肉先死。此皆肌肉之诊也。由是约而言之。当以坚脆诊寿夭。以
肥瘦诊血气。以有泽无泽诊盛衰。以消减壅肿诊虚实。八者交推。则诊候之法备。而肌肉之证明。所谓肌
者。四肢间附骨之肉也。 者。肘膝后如块之肉也。曰 曰谷。则以血之流注。如水之流注。水注川曰 。注
曰谷也。若夫形盛脉细。少气不足以息者危。形瘦脉大。胸中多气者死。是又合脉以观之。因症以辨之。
审其顺逆。而判其吉凶矣。大凡诊法。皆当错综相参。非独诊肌云尔。
《内经》说：肝主管身体的筋膜。脾主管身体的肌肉。肌肉汇聚较大的部位称为“谷”。肌肉汇聚较小的部位称为“䐃”（音同“分”，指肌肉间隙）。在分肉之间，是“谷”的会合之处，用来运行营气和卫气，并汇聚大气。圣人对这一点，再三强调其重要性。况且脾胃属土，其充养的部位在肌肉。所以观察肌肉的消长变化，就可以知道脾胃功能的盛衰。脾是孤脏，负责将精气灌溉到四肢百骸。胃是五脏六腑禀受气血的来源。诊脉虽然以胃气为根本，但望诊形体应当以肌肉为首要。如果形体消瘦、肌肉脱失，即使九候脉象调和，圣人不说可以生还，而说如同死亡一样。那么肌肉的消长，尤其关系到胃气的有无。诊察的方法，怎么能不深入研究呢？
具体分析如下：如果形体充实，且大肌肉坚实且有纹理分界，这叫“肉坚”，肉坚的人长寿。如果形体充实，但大肌肉没有纹理分界且不坚实，这叫“肉脆”，肉脆的人短命。肥胖且润泽的，说明血气有余。肥胖但不润泽的，说明血有余而气不足。消瘦且不润泽的，说明血气都不足。消瘦但润泽的，说明血不足而气有余。肥胖的人耐寒，消瘦的人耐热。肌肉瘦削的是脾虚，肌肉壅肿的是脾实。肌肉跳动的是脾有热病，肌肉松弛下垂的是脾中风气。筋惕肉瞤（肌肉跳动）的是阳虚。食欲减退、肌肉消瘦的是意志受损（或脾气受损）。肌肉极度瘦削干枯发黑，是“肉极”的证候。肌肉萎软无力，是“肉痿”的征象。皮肤起鸡皮疙瘩，是寒邪客于皮肤。肌肤麻木不仁，是邪气侵入络脉。肌肉充盛，是形气有余。肌肉消减，是形气不足。肥胖人肌肉像棉絮一样松软，叫做“无气”。妇人肌肉像鱼鳞一样干燥粗糙，叫做“带下”病。骨痛且肌肉枯槁，是寒胜热。肌肉腐烂，是热胜寒。疳病导致形体羸瘦，病症起源于肠胃内部。瘅疟导致肌肉消烁，邪气停留在分肉之间。肌肉脱失者死，破腘（膝盖后窝破裂）者死。大肌肉陷下，大骨枯槁者皆死。肌肉不滑润，肌肉饱满且嘴唇外翻者，肌肉先死。麻风病疼痛剧烈如刀割却感觉不到痛，是肌肉先死。肌肉痿软，嘴唇外翻，人中穴处饱满者，肌肉先死。这些都是关于肌肉的诊察方法。
综上所述，简要概括来说：应当通过肌肉的坚实与脆弱来诊察寿命的长短；通过肥胖与消瘦来诊察血气的盈亏；通过是否有光泽来诊察盛衰；通过消减与壅肿来诊察虚实。这八方面综合推究，诊察的方法就完备了，肌肉的病情也就明确了。所谓“肌”，是指四肢间附着在骨头上的肉。“䐃”（或作“腘”相关部位），是指肘膝后方像块状隆起的肉。称为“䐃”和“谷”，是因为血液的流注，就像水的流注一样。水流注入河道称为“川”，注入深潭称为“谷”。如果形体盛大但脉象细弱，气息短少不足以呼吸，这是危症。形体消瘦但脉象洪大，胸中气多，这是死症。这是又要结合脉象来观察，根据症状来辨别，审察病情的顺逆，从而判断吉凶。大凡诊法，都应当错综参互，不仅仅局限于诊察肌肉而已。
The *Classic of Internal Medicine* states: The Liver governs the sinews (tendons and ligaments) of the body. The Spleen governs the muscles of the body. The large convergence points of muscles are called "Gu" (Valleys). The small convergence points of muscles are called "Chun" (referring to muscle intervals). Between the separated muscles, these are the meeting places of the "Gu", where Ying Qi (Nutrient Qi) and Wei Qi (Defensive Qi) circulate, and where Da Qi (Great Qi) gathers. The Sages have emphasized this point repeatedly. Furthermore, the Spleen and Stomach belong to Earth, and their nourishment manifests in the muscles. Therefore, by observing the increase or decrease of muscles, one can ascertain the prosperity or decline of the Spleen and Stomach functions. The Spleen is the solitary Zang organ that irrigates the four extremities. The Stomach is the source from which the Five Zang and Six Fu organs derive their Qi. Although pulse diagnosis takes Stomach Qi as the root, visual inspection of form should prioritize the muscles. If the body is emaciated and muscles are wasted away, even if the Nine Pulses are harmonious, the Sages do not say the patient can survive, but rather liken it to death. Thus, the fluctuation of muscles is particularly critical regarding the presence or absence of Stomach Qi. How can we not study the methods of diagnosis?
Analyzing in detail: If the body is robust, and the large muscles are firm with clear textural divisions, this is termed "firm muscles" (Rou Jian); those with firm muscles live long. If the body appears robust, but the large muscles lack texture and are not firm, this is termed "fragile muscles" (Rou Cui); those with fragile muscles die young. Those who are obese and lustrous have an excess of Blood and Qi. Those who are obese but not lustrous have excess Blood but deficient Qi. Those who are thin and not lustrous have deficiency of both Blood and Qi. Those who are thin but lustrous have deficient Blood but excess Qi. Obese individuals tolerate cold well; thin individuals tolerate heat well. Emaciated muscles indicate Spleen Deficiency; swollen and congested muscles indicate Spleen Excess. Twitching muscles indicate Heat pathology in the Spleen; flaccid and sagging muscles indicate Wind striking the Spleen. Trembling sinews and twitching muscles (Jin Ti Rou Yu) indicate Yang Deficiency. Reduced appetite and muscle wasting indicate impairment of Yi (Intellect/Spleen Spirit). Extreme emaciation, dryness, and blackening of muscles represent the syndrome of "Extreme Muscle Wasting" (Rou Ji). Flaccid and weak muscles are signs of "Muscle Flaccidity Syndrome" (Rou Wei). Gooseflesh on the skin indicates Cold pathogen invading the skin. Numbness of skin and flesh indicates Evil entering the Luo (Collateral) vessels. Full and robust muscles indicate excess of Form and Qi. Wasted muscles indicate deficiency of Form and Qi. Obese individuals with cotton-like soft muscles are described as having "No Qi". Women with fish-scale-like dry skin are diagnosed with "Dai Xia" (Leukorrhea). Bone pain with withered muscles indicates Cold overcoming Heat. Rotting flesh and decaying muscles indicate Heat overcoming Cold. Malnutrition disease (Gan Bing) causing emaciation originates internally within the Intestines and Stomach. Malaria with intense heat (Dan Nue) causing muscle wasting indicates Evil lodged between the separated muscles. Wasted muscles signify death. Rupture of the popliteal fossa signifies death. Sunken large muscles and withered large bones both signify death. Muscles lacking lubrication, full muscles with everted lips, indicate the muscles are dying first. Leprosy with cutting pain yet insensitivity indicates the muscles are dying first. Flaccid muscles, everted lips, and fullness at the philtrum indicate the muscles are dying first. These are all diagnoses related to muscles.
Summarizing briefly: One should diagnose longevity through the firmness or fragility of muscles; diagnose the balance of Blood and Qi through obesity or thinness; diagnose prosperity or decline through luster or dullness; diagnose Excess or Deficiency through wasting or swelling. By comprehensively analyzing these eight aspects, the diagnostic methods become complete, and the conditions of the muscles become clear. What is referred to as "Ji" (Muscle proper) refers to the flesh attached to the bones in the limbs. What is referred to as "Chun" (or specific muscle masses) refers to the fleshy masses behind the elbows and knees. They are called "Chun" and "Gu" because the flow of blood is like the flow of water. Water flowing into rivers is called "Chuan"; water pooling into deep basins is called "Gu". If the body appears robust but the pulse is fine/thin, and there is shortness of breath insufficient for respiration, this is a critical condition. If the body is thin but the pulse is large, and there is excessive Qi in the chest, this is a fatal condition. This requires combining pulse observation with symptom differentiation, assessing the course of the disease (Shun/Ni), and judging auspiciousness or misfortune. Generally, all diagnostic methods should be cross-referenced and integrated, not limited solely to the diagnosis of muscles.