The Thai Sip Sen Energy Lines are the ten main Lom Pran Channels that distribute Life Force Energy through the body. It’s a common thought and the official stance in Thailand that the Sen Lines all start around the navel in the abdominal area and — except for Sen Kalathari — all end at different orifices of the body, such as the nostrils, mouth, eyes, ears, anus, and genitals.
Nevertheless, there are some Thai Massage schools and lineages that claim that (some of) the Sen Lines start at the orifices (openings) of the body and not at the navel area, but in contrast end near or around the navel. So, how come that there’s this difference, and is it important?
First of all, the question of where the Sen Lines start is of some importance because it’s also thought that the Sen starting points are the location where Lom Pran Life Force enters the Energy Channels. It means that these starting or entry points need to be “open” to let Life Force enter unobstructed. Subsequently, in Thai Massage there’s always some extra attention on opening the so-called “Wind Gates.” By the way, Wind Gates can refer to Prana entry points but also to exit points.
Looking at it from out the development of the human body it would make sense that the Sen Lines start around the navel area because an embryo in the uterus is fed through the navel string (umbilical cord) which is attached to the placenta of the mother. It’s the only place of contact with Life Force Energy, which comes to the blood supply that runs through the navel string.
Now, after a baby is born it’s thought that it will get its Prana Life Force Energy supply through different ways: through the air it breathes in, through food, through barefoot contact with the Earth, and through sunlight which penetrates the skin (or even through the eyes, mouth, and ears). So, by some it’s believed that Sen Ittha and Sen Pingkhala, which both have Sen Endpoints at the left and right nostril are actually thought to be the locations of input (Starting Point) of Prana and not output (Endpoint). Hence, some lineages see the nostrils as Sen Starting Points and not Endpoints.
The same counts for Sen Sumana, for instance, which typically would start above the navel and end in the mouth, but then some Thai Massage lineages say it starts in the mouth and ends at the navel. There are more examples to give, basically for almost all the Sen Energy Lines. In fact, the thing is that it isn’t unambiguously clear where the Sen Lines start or end, even if two Thai Healing Arts lineages have the same construct of the Sen trajectories through the body.
But there’s even more to it, because some lineages say that Lom Pran (Prana) is only distributed through the principal Sen Sumana line to all the other Sen Lines, which is an idea we also find in the concept of the Yoga Nadis. This idea would make that wherever Prana comes from it would first go through the gross body — which could be the nostrils, mouth, eyes, skin, etc. — and then via Sen Sumana finally to the subtle body, also known as the Pranic Body or the Pranamayakosha.
A persistent idea is that Sen Sumana starts near the navel, which is also a common thought in the Indic Yoga Nadi system (where it’s called Sushumna Nadi, being the similar energy channel as the Sen Sumana channel), but if it would start in the mouth, well, why not? The point is that at some moment Prana Life Force is converted from it’s gross aspect to its subtle aspect and in practice it doesn’t really matter where and how exactly that happens.
As for working with the Sen Lines, as long as you work on all the Sen Lines — through massage, acupressure, stretches, herbal compresses, etc. — you will keep them open to let Prana Life Force come in and to let superfluous, circulated, or stagnant Prana get out, and then … who cares what’s the Starting Point or Endpoint of a given Sen Line?
So, although an interesting “philosophical” or “technical” discussion, I don’t see how the one or the other, that is, where a Sen Energy Line starts or ends makes a real difference in how you would work with the body. You would always already work on resolving constrictions, tensions, energy excesses or energy depletions of the Sen Lines, so whether you work on the beginning, end, or any other part in-between of a Sen Channel has little to do with the therapeutic work that needs to be done anyway.