Kang Youwei's teacher, Zhu Jiujiang, said when he taught Kang Youwei to have a flat wrist: "When the wrist is flat, the glass of water should be placed on it and not tilted." Obviously, by wrist level, he means that the two joints of the wrist are level with the desktop, or similar to the wrist state when the palm is down and the arm is naturally straight.
The so-called "wrist flat" should be opposite to "wrist pressure" and "wrist vertical", which does not mean that the two joints of the wrist are flush with the desktop. Huang Jian, chairman of the Hong Kong Calligraphers Association, said: "The wrist moves up and down, and the center position is flat, that is, flat wrist. The lower part is wrist pressure, and the upper part is usually called vertical palm. " This explanation should be more reasonable than Zhu Jiujiang's. This kind of "flat wrist" will be more natural when writing without "twisting the ribs to buckle".