One of the principles of Sen Line theory is that all the Sib Sen Energy Lines start around the navel (the umbilicus or belly button). Nevertheless, there are contrasting views about where exactly around the navel they have their beginnings.
Some say all the lines start just below the navel, others say around it in a circle, others claim they start near the solar plexus, and again others state that all start from one single point near the navel. Moreover, the distances to the navel are measured in “finger-wide” or “thumb-wide” distances, which up to today is a point of both discussion and confusion.
In any case, there’s one thing all theories agree on, and that is that the area of the navel is the starting point of all the Sib Sen. This of course is not so strange, because we just need to think about how a human being develops in the uterus: the connection with the mother is through the umbilical cord (attaching the baby to the placenta in the mother’s womb) which supplies blood, nutrition, oxygen, and according to Asian concepts Prana or Vital Life Energy.
As long as a baby is in the womb, the only way to absorb Prana is through the umbilical cord which attaches to the baby’s navel area. In that sense it’s only logical that the Sen Energy lines start there also.
Later, when the baby is born, Prana absorption takes place through the air it breathes and the food it eats, and also through sunlight that penetrates its skin.
Nevertheless, the starting points of the Sen continue to be important to be “open and unblocked” because as far as the theory goes they are still the starting points for Prana distribution. Subsequently, lots of Thai acupressure work is done also on these points around the navel, an area often rather contracted and tensed, with lots of knots, tangles and adhesions to be worked on and released.