《黄帝内经·素问·骨空论》
扁骨，有血脉渗灌的纹理内外交流，没有直通骨髓的孔穴，所以没有骨空的穴位。
扁骨有渗理凑，无髓孔，易髓无空。
Flat bones have a blood supply that flows back and forth on the inside and outside, and there are no holes that lead directly to the bone marrow, so there are no hollows.