系于脐。其病于内为内急。为心承伏梁。如梁之伏于心下。而上承于心也。其病在外当筋之所过者。
为转筋筋痛。治在燔针劫刺。其成伏梁而唾脓血者。此病在心脏。故为死不治。其病在气而为筋经
之病者。寒则反折筋急。热则筋纵不收。阳急则反折。阴急则俯不能伸。盖少阴本阴而标阳。故有
寒热阴阳之证。少阴之从本从标也。丑者十二月。少阴主气。故为季冬之痹。夫天为阳。地为阴。
日为阳。月为阴。岁半以上。天气主之。岁半以下。地气主之。故三阳之气。主于春夏。三阴之气。
主于秋冬。此阴阳之所以系天地日月。而人亦应之。尚御公曰。腹为阴。背为阳。阳急则反折。
阴急则不伸。手少阴之筋。只循于胸腋脐腹。而不经于背。所谓阳急则反折者。病足少阴之筋也。
足少阴之筋。循脊内挟膂。上至项。此阴阳相合。水火气交。故手足少阴。皆有阴阳寒热之俯仰。
张开之曰。此下六篇。论筋之所经。骨脉之度量。荣卫之循行。只论筋有痹证者。盖假病以明筋之
合于三阴三阳。天之四时六气。
足之阳明。手之太阳。筋急则口目为 。 急不能卒视。治皆如右方也。（ 僻同即口僻之义）
尚御公曰。此申明手足阴阳之筋。皆分循于左右。故复以口目之 僻以证之。足阳明之筋。上
挟口为目下纲。手太阳之筋。结于颔。属目外 。故二经之左筋急。则口僻于左。而当刺其左。右
筋急。则口僻于右。而当取
之右。如左目不能卒视。其病在左。右目不能卒视。其病在右。如两目皆急。则左右皆病。故治法
皆如右方。而其病则有左右之分也。
（足少阴之筋）系结于肚脐。其病在体内表现为腹部拘急疼痛，以及心脏下方伏梁病，就像梁木伏在心下，向上支撑于心胸部位。其病在体表则沿着筋脉所经过的部位，出现转筋和筋痛。治疗采用燔针劫刺法。如果形成伏梁病且咳吐脓血，这是病位在心脏，所以属于死证，无法治愈。如果病在气分而成为筋经的病，受寒则筋脉反折拘急，受热则筋脉弛缓不能收摄。阳侧拘急则身体向后反折，阴侧拘急则身体前屈不能伸展。这是因为少阴经本属阴而标属阳，所以有寒热阴阳的证候表现。少阴经可以从本也可以从标。丑月是十二月，少阴经主令，所以是季冬季节的痹证。天为阳，地为阴；日为阳，月为阴。上半年天气主导，下半年地气主导。所以三阳之气主宰春夏，三阴之气主宰秋冬。这就是阴阳与天地日月相联系的道理，人也顺应这一规律。尚御公说：腹部属阴，背部属阳。阳侧拘急则身体后仰反折，阴侧拘急则身体前屈不能伸展。手少阴之筋，只循行于胸、腋、脐、腹，而不经过背部。所谓“阳急则反折”，指的是足少阴之筋的病。足少阴之筋，循行于脊柱内部，夹持脊旁肌肉，上行至项部。这是阴阳相合，水火气交的结果，所以手足少阴之筋都有阴阳寒热导致的前俯后仰病变。张开之说：以下六篇，论述筋脉的循行路线、骨脉的长度度量、营卫的循行路径，只讨论筋有痹证的情况，大概是借病症来说明筋脉与三阴三阳、天之四时六气的契合关系。
足阳明经和手太阳经的筋脉发生拘急，会导致口眼歪斜。拘急严重时不能突然看清事物，治疗方法都如同上述方法。（“ ”同“僻”，即口眼歪斜的意思）尚御公说：这里阐明手足阴阳之筋，都是分别循行于身体左右两侧，所以再次以口眼歪斜来证明这一点。足阳明之筋，上行挟持口部，作为目下的纲领；手太阳之筋，结聚于下颌，连属于目外眦。所以这两条经脉左侧筋脉拘急，则口眼向左侧歪斜，应当针刺左侧；右侧筋脉拘急，则口眼向右侧歪斜，应当取治右侧。如左眼不能突然看清，病在左侧；右眼不能突然看清，病在右侧。如果双眼都拘急，则左右两侧都有病。所以治疗方法都如同上述方法，但病情则有左右之分。
(The Foot-Shaoyin tendon channel) is tied to the navel. When diseased internally, it causes abdominal urgency and pain, and Chengfu Liang (Volute Beam disease) supporting the heart, resembling a beam lying beneath the heart and extending upward to support the heart region. When diseased externally, along the course of the tendons, it presents as muscle cramps and tendon pain. Treatment involves burning needle (Fanzhen) rapid puncture (Jiesi). If Volute Beam disease develops with expectoration of pus and blood, this indicates the disease is in the Heart; thus, it is a fatal condition that cannot be cured. If the disease affects Qi and becomes a disorder of the tendon channels, cold causes the tendons to reverse and become rigid, while heat causes the tendons to relax and fail to contract. Yang-side rigidity leads to backward arching (opisthotonos), and Yin-side rigidity leads to forward flexion inability to extend. This is because Shaoyin is fundamentally Yin but has Yang as its manifest aspect, hence presenting with cold-heat and Yin-Yang syndromes. Shaoyin can follow either its root or its branch. The month of Chou (the twelfth lunar month) is governed by Shaoyin Qi, making it the Bi syndrome of late winter. Heaven is Yang, Earth is Yin; the Sun is Yang, the Moon is Yin. In the first half of the year, Heavenly Qi dominates; in the second half, Earthly Qi dominates. Thus, the Qi of the Three Yangs governs Spring and Summer, and the Qi of the Three Yins governs Autumn and Winter. This is how Yin and Yang relate to Heaven, Earth, Sun, and Moon, and humans correspond accordingly. Shang Yu Gong stated: The abdomen is Yin, the back is Yang. Yang-side rigidity causes backward arching, while Yin-side rigidity prevents extension. The Hand-Shaoyin tendon channel only follows the chest, axilla, navel, and abdomen, without traversing the back. Therefore, "Yang-side rigidity causes backward arching" refers to the pathology of the Foot-Shaoyin tendon channel. The Foot-Shaoyin tendon channel runs inside the spine, flanking the paraspinal muscles, ascending to the nape. This represents the combination of Yin and Yang, and the intersection of Water and Fire Qi; thus, both Hand and Foot Shaoyin tendon channels exhibit forward-flexion and backward-extension pathologies due to Yin-Yang and cold-heat factors. Zhang Kai stated: The following six chapters discuss the courses of tendons, measurements of bone vessels, and circulation of Ying and Wei Qi. They only discuss tendon Bi syndromes, presumably using pathology to clarify the integration of tendons with the Three Yin and Three Yang meridians and the Six Qi of the four seasons of Heaven.
When the tendons of the Foot-Yangming and Hand-Taiyang are rigid, they cause deviation of the mouth and eyes (Kou Pi). Severe rigidity prevents sudden clear vision. The treatment methods are the same as those described above. (" " is synonymous with "Pi", meaning deviation of the mouth and eyes). Shang Yu Gong stated: This clarifies that the tendons of the Hand and Foot Yin and Yang meridians run separately on the left and right sides. Therefore, deviation of the mouth and eyes is used as evidence. The Foot-Yangming tendon ascends to flank the mouth, serving as the framework for the lower eyelid. The Hand-Taiyang tendon knots at the chin and connects to the outer canthus of the eye. Thus, if the tendons on the left side of these two meridians are rigid, the mouth and eyes deviate to the left, and the left side should be needled. If the tendons on the right side are rigid, the mouth and eyes deviate to the right, and the right side should be treated. If the left eye cannot see suddenly, the disease is on the left; if the right eye cannot see suddenly, the disease is on the right. If both eyes are rigid, both left and right sides are diseased. Therefore, the treatment methods are all as described above, although the pathology may differ between left and right.