（素问骨空论）
辅骨上横骨下为楗，（辅骨，膝辅骨。横骨，前阴横骨。是楗为股骨也。楗音健，刚木。）挟髋为机，（髋，尻也，即
臀也，一曰两股间也。机，枢机也。挟臀之外，即楗骨上运动之机，故曰挟髋为机，当环跳穴处是也。髋音宽。 音
谁。）膝解为骸关，（骸，说文云∶胫骨也。胫骨之上，膝之节解也，是为骸关。骸音鞋。）挟膝之骨为连骸，（膝上两侧，
皆有挟膝高骨，与骸骨相为接连，故曰连骸。）骸下为辅，（连骸下高骨，是为内外辅骨。）辅上为 ，（辅骨上向膝后曲
处为 ，即委中穴也。 音国。） 上为关，（ 上骨节动处，即所谓骸关也。）头横骨为枕。（脑后横骨为枕骨。）水俞五
十七穴者，尻上五行行五，伏菟上两行行五，左右各一行行五，踝上各一行行六穴。（此与水热穴论同，亦骨空也，故并
及之，详针刺类三十八。菟，兔、徒二音。）髓空在脑后五分，在颅际锐骨之下，（髓，脑髓也。髓空，即风府也，在脑
后入发际一寸，督脉穴。）一在龈基下，（唇内上齿缝中曰 交，则下齿缝中当为 基，今曰 基下者，乃颐下正中骨罅
也。王氏曰∶当颐下骨陷中有穴容豆，中诰图经名下颐。 音银。）一在项后中、复骨下，（即大椎上骨节空也。复当作
伏，盖项骨三节不甚显，故云伏骨下也。）一在脊骨上空、在风府上。（风府上，脑户也，督脉穴。）脊骨下空，在尻骨下
空。（脊骨之末为尻骨。尻骨下空，长强也，督脉穴。）数髓空，在面挟鼻，（数，数处也。在面者，如足阳明之承泣、巨
，手太阳之颧 ，足太阳之睛明，手少阳之丝竹空，足少阳之瞳子 、听会。挟鼻者，如手阳明之迎香等处。皆在面
之骨空也。）或骨空在口下，当两肩。（足阳明大迎分也，亦名髓孔。）两膊骨空，在膊中之阳。（膊，肩膊也。中之阳，
肩中之上 也，即手阳明肩 之次。）臂骨空，在臂阳，去踝四寸，两骨空之间。（臂阳，臂外也。去踝四寸两骨之间，
手少阳通间之次也，亦名三阳络。）股骨上空在股阳，出上膝四寸。（股阳，股面也。出上膝四寸，当足阳明伏兔、阴市
之间。） 骨空，在辅骨之上端。（ ，足胫骨也。 骨之上为辅骨。辅骨之上端，即足阳明犊鼻之次。 ，形敬切，又
音杭。）股际骨空，在毛中动下。（毛中动下，谓曲骨两旁股际，足太阴冲门动脉之下也。）尻骨空，在髀骨之后，相去四
寸。（即尻上两旁，足太阳八 穴也。）扁骨有渗理凑，无髓孔，易髓无空。（扁骨者，对圆骨而言。凡圆骨内皆有髓，有
髓则有髓孔。若扁骨则但有血脉渗灌之理凑而内无髓，故凡诸扁骨以渗灌易髓者，则无髓亦无空矣，此胁肋诸骨之类是
也。）
(Su Wen: Gu Kong Lun)
The area above the auxiliary bone of the knee and below the transverse bone of the anterior genitalia is called "Jian" (Key/Beam). (Auxiliary bone refers to the bones surrounding the knee. Transverse bone refers to the horizontal bone in the anterior genital region. The so-called "Jian" is the femur. Jian is pronounced jiàn, meaning hard wood.)
The areas flanking the hips are called "Ji" (Pivot/Hinge). (Kuan refers to the sacrococcygeal region, i.e., the buttocks; alternatively, it refers to the space between the thighs. Ji refers to the pivot mechanism. Outside the buttocks, this is the pivot of movement for the upper part of the Jian bone, hence called "flanking the kuan for Ji," corresponding to the location of the Huantiao acupoint. Kuan is pronounced kuān. Shui is pronounced shuí.)
The joint resolution at the knee is called "Hai Guan" (Skeleton Gate). (Hai, according to Shuo Wen Jie Zi, refers to the tibia. Above the tibia, at the joint line of the knee, is the Hai Guan. Hai is pronounced hái.)
The bones flanking the knee are called "Lian Hai" (Connected Skeletons). (On both sides above the knee, there are high bones adjacent to the knee, connecting with the Hai bone, thus called Lian Hai.)
Below the Lian Hai is the auxiliary bone. (The high bone below the Lian Hai constitutes the medial and lateral auxiliary bones.)
Above the auxiliary bone, curving towards the back of the knee, is "Guo". (Above the auxiliary bone, where it curves towards the popliteal fossa, is called "Guo," which is the Weizhong acupoint. Guo is pronounced guó.)
Above Guo is the Guan (Gate/Joint). (Above Guo, at the site of bone joint movement, is what was previously referred to as the Hai Guan.)
The transverse bone of the head is the occipital bone. (The transverse bone at the back of the head is the occipital bone.)
There are fifty-seven water-shu points, distributed in five rows above the sacrum, five per row; two rows above the Futu point, five per row; one row on each side, five per row; and one row above each ankle, six per row. (This corresponds to the Water-Heat Acupoints discussion in Su Wen, also belonging to the category of bone spaces, hence mentioned together; see detailed explanation in Needling Category 38. Tu is pronounced rù or tú.)
The Marrow Space (Sui Kong) is located five fen behind the head, below the sharp bone at the temporal margin. (Marrow refers to brain marrow. The Sui Kong is the Fengfu acupoint, located one cun inside the posterior hairline, belonging to the Du Meridian.)
Another is below the Yin Ji. (The gum junction inside the upper teeth is called Jiao; thus, the lower gum junction should be Ji. The current term "below Ji" refers to the gap in the central bone of the chin. Wang Shi states: There is an acupoint in the depression of the chin bone that can hold a bean, named Xiayi in the Ming Tang Acupoint Atlas. Yin is pronounced yín.)
One is in the center of the neck, below the hidden (lying down) bone. (This is the empty space at the vertebral segment above Dazhui. "Fu" should be read as "Fu" (lying/prone), as the three cervical vertebrae are not very prominent, hence described as below the lying-down bone.)
One is in the empty space above the spinal bone, above Fengfu. (Above Fengfu is Naohu, an acupoint of the Du Meridian.)
The empty space below the spinal bone is the empty space below the sacral bone. (The end of the spinal bone is the sacrum. The empty space below the sacrum is Changqiang, an acupoint of the Du Meridian.)
Multiple Marrow Spaces on the face flanking the nose. (Shu means multiple locations. Those on the face include Chengqi and Juliao of the Foot-Yangming Stomach Meridian, Quanliao of the Hand-Taiyang Small Intestine Meridian, Jingming of the Foot-Taiyang Bladder Meridian, Sizhukong of the Hand-Shaoyang Sanjiao Meridian, Tongziliao and Tinghui of the Foot-Shaoyang Gallbladder Meridian. Flanking the nose include Yingxiang of the Hand-Yangming Large Intestine Meridian, etc. All these are bone spaces on the face.)
Some bone spaces are below the mouth, directly opposite the shoulders. (This is the boundary of Daying of the Foot-Yangming Stomach Meridian, also known as Sui Kong.)
The bone spaces of both arms are located at the Yang aspect of the arm. (Bo refers to the shoulder/arm. Zhong zhi Yang refers to the upper-middle part of the shoulder, which is the next point after Jianyu of the Hand-Yangming Large Intestine Meridian.)
The bone space of the arm is on the Yang aspect of the arm, four cun from the ankle, between the two bones. (Arm Yang refers to the lateral aspect of the arm. Four cun from the ankle between the two bones is the next point after Tongjian of the Hand-Shaoyang Sanjiao Meridian, also known as Sanyangluo.)
The bone space above the femur is located at Guyang, four cun above the knee. (Guyang refers to the anterior aspect of the thigh. Four cun above the knee is between Futu and Yinshi of the Foot-Yangming Stomach Meridian.)
The bone space of the tibia is at the upper end of the auxiliary bone. (Xing refers to the tibial bone. Above the tibia is the fibula. The upper end of the fibula is the next point after Dubi of the Foot-Yangming Stomach Meridian. Xing is pronounced xíng jìng qiē, or háng.)
The bone space at the groin is below the moving artery in the pubic hair region. (Mao zhong dong xia refers to the area beside Qugu in the groin, below the Chongmen acupoint of the Foot-Taiyin Spleen Meridian where the pulse moves.)
The bone space of the sacrum is behind the hip bone, four cun apart. (This refers to the Ba Liao acupoints of the Foot-Taiyang Bladder Meridian on both sides above the sacrum.)
Flat bones have converging permeation textures but no marrow pores; they use permeation instead of marrow and thus have no empty spaces. (Flat bones are contrasted with round bones. Round bones internally contain marrow and thus have marrow pores. Flat bones, however, only have the convergence of blood vessel permeation textures without internal marrow. Therefore, flat bones that rely on permeation rather than marrow have neither marrow nor empty spaces; this applies to the ribs and other such bones.)