Objectives :
This studies were designed to formulate the basic theory about Meridian-muscle(經筋) and identify the inevitable relationship between Meridian-muscle and muscular system by analyzing the properties of Trains of Meridian-muscle(經筋流走) with anatomy.

Methods :
In this study, the meaning of ‘Geun(筋)’ and ‘Three Eum Three Yang(三陰三陽)’ which are the technical terms of Meridian-muscle were investigated, and researched the posture that forms the basis of the description. Furthermore, the meaning and relationship were analyzed logically with ‘Geun(筋)’, ‘GeunMag(筋膜)’, ‘Yug(肉)’, and ‘Gi(肌)’, which were described in ≪HwangJeNaeGyeong(黃帝內經)≫, and then the original meanings of ‘Geun(筋)’ were examined as compared with the anatomic and histologic observations. The meaning of the Trains of Meridian-muscle(經筋流走) was reinterpreted on the basis of this research.

Results :
Firstly, our studies discovered that the textual analysis of ≪Yeongchu·GyeongGeun(靈樞·經筋)≫ made it possible to draw the underlying theory. Next, they revealed that there is a basic posture behind ≪Yeongchu·GyeongGeun(靈樞·經筋)≫ description and Three Eum(三陰) and Three Yang(三陽) meant the body parts on the basis of ≪Somun·EumYangLiHabLon(素問·陰陽離合論)≫. Lastly, the meaning of ‘Geun(筋)’ and ‘Yug(肉)’ was confirmed using anatomy through the textual analysis of ≪HwangJeNaeGyeong(黃帝內經)≫.

Conclusions :
There is a basic posture that is the basis for describing the Trains of Meridian-muscle(經筋流走). The basic posture is a standing position with head, eyes, and toes directed anteriorly forward, arms adjacent to the sides with the back of the hand faces lateral with spread out the fingers and the thumbs neutral, and lower limbs close together with the feet parallel. This posture can be the basis of all areas of Acupuncture Medicine, and defined as the ‘Acupuncture Medical Position’.
Three Eum Three Yang(三陰三陽) of ≪Somun·EumYangLiHabLon(素問·陰陽離合論)≫ means the description of the body part. Greater Yang(太陽) is the posterior of the body, Lesser Yang(少陽) is the lateral of the body, and Yang Brightness(陽明) is the anterior of the body. Three Eum(三陰) means the inside of the human body in the trunk, but in the leg, it means the part where the both legs are contacted. The name of the individual Meridian-muscle is thought to be given according to the name of a Meridian-muscle that located the part corresponding to Three Eum Three Yang(三陰三陽).
The ‘GeunMag(筋膜)’ of ≪HwangJeNaeGyeong(黃帝內經)≫ means tendon, the ‘Geun(筋)’ means the fascia of the whole body sensu lato and the myofasica sensu stricto which includes the epimysium and the perimysium. ‘Yug(肉)’ can be seen as endomysium and muscle fibers. And ‘Geun(筋)’ can be seen as tendon and ligament that an extension of myofascia. Muscle''s categories include all four of these, so it is reasonable to use ‘muscle’ as ‘GeunYug(筋肉)’.
The reason why it is possible to describe the word ‘Meridian-muscle(筋經)’ is because fascia has continuity. ‘Meridian-muscle(筋經)’ can be defined as the system of longitudinal muscles and myofascia in the whole body that encompasses dynamics.
Foot Greater Yang Meridian-Muscle(足太陽之筋) is construed as a series of muscles including peroneus brevis m., abductor digiti minimi m., lateral band of plantar aponeurosis, gastrocnemius m., soleus m., hamstring m., deep part of gluteus maximus m., sacrotuberous ligament, erector spinae m.(include spinalis m., semispinal m., multifidus m., rotatores m., longissimus m., iliocostalis m., intertransversarii m.), omohyoid m., occipitofrontal m., epicranial aponeurosis, orbicularis oculi m., ascending part of trapezius m., latissimus dorsi m., descending part of trapezius m. and platysma m..
Foot Lesser Yang Meridian-Muscle(足少陽之筋) is construed as a series of muscles including extensor digitorum longus m., peroneus tertius m., peroneus longus m., iliotibial tract, vastus lateralis m., superior part and superficial fibers of inferior part of gluteus maximus m., obliquus externus abdominis m., serratus anterior m., pectoralis minor m., intercostal m., scalene m., temporalis m., temporoparietalis m., and temporal fascia and link of orbicularis oculi m..
Foot Yang Brightness Meridian-Muscle(足陽明之筋) is construed as a series of muscles including extensor digitorum brevis m., extensor digitorum longus m., gluteus medius m., gluteus minimus m., tensor fasciae latae m., obliquus abdominis m., transversus abdominis m., link of thoracolumbar fascia, tibialis anterior m., patella to patellar ligament, vastus intermedius m., rectus femoris m., rectus abdominis m., sternalis m., sternohyoid m., sternothyroid m., geniohyoid m., mylohyoid m., hyoglossus m., stylohyoid m., anterior belly of digastric m., depressor anguli oris m., depressor labii inferioris m., mentalis m., orbicularis oris m., levator labii superioris m., zygomaticus major·minor m., levator anguli oris m., inferior part of orbicularis oculi m., levator labii superioris alaque nasi m., lateral pterygoid m. and masseter m..
Foot Greater Yin Meridian-Muscle(足太陰之筋) is construed as a series of muscles including abductor hallucis m., flexor hallucis longus m., vastus medialis m., adductor brevis m., pectineus m., sartorius m., pyramidalis m., linea alba, obliquus abdominis m. and transversus abdominis m..
Foot Lesser Yin Meridian-Muscle(足少陰之筋) is construed as a series of muscles including flexor digitorum longus m., superficial and deep intrinsic foot muscle, quadratus plantae m., adductor hallucis m., adductor longus m., iliopsoas m. for iliacus m. and psoas major·minor m., anterior longitudinal ligament, posterior longitudinal ligament, quadratus lumborum m. and longus colli m. and longus capitis m..
Foot Reverting Yin Meridian-Muscle(足厥陰之筋) is construed as a series of muscles including extensor hallucis longus m., extensor hallucis brevis m., lower part of inferior extensor retinaculum in tibialis anterior m., tibialis posterior m., interosseous membrane, popliteus m., adductor magnus m., obturator internus m. and all muscles connected to the hip joint.