The name of this point is 四讀, Shi Toku (Japanese) or Si Du (Chinese). It means “Four Rivers”. Apparently, it indicates the region in China where the Yellow River and three other large rivers merge, and the name suggests “big currents”. I think it is reasonable to assume that this point is where big currents of Blood or Qi occur.
In health there is freedom. Health is the first of all liberties.” ~ Henri Frederic Amiel