your post made me think of some random connections, so ill share:
--i have participated twice in a 10-day Vipassanna meditation retreat (i have written a post in the past about it--somewhere in here). aside from long hours of meditating, the retreat also consists of daily dharma lectures by the current head of Vipassana. I am specifically reminded of his talks for 2 reasons:
--he mentioned that his teacher and predesesor had nasty migraines, and it was his claim that Vipassanna meditation cured him of it, and was thus the reason why he got so serious about it
--in the talks, questions of existenialism, ontology, epistomology, etc, were constantly at the forefront, i think because one of the goals of meditating is to do a sort of self-audit wherein one examines very closely how real-world stimulae gets interpreted and internalized by the body. in the Vipassanna view, i think, it is thought that anything which the body experiences as a sensation is real in the sense that that body takes it on--thus the experience to the person is indeed real. However, the teaching is that we as humans have the ability to perceive with great focus how most of those felt sensations are actually caused by us in our own minds (thus, the nutz and bolts of the meditation is to learn how to recognize how/when we create sensations for ourselves, as well as to dig up old experiences where sensations are still alive in the body).
--also, for what it is worth, regarding the element of ki, it is interesting to note that we were specifically told NOT to incorporate any outside practices that we had, including anything having to do with "chi" or "ki". I never quite figured out why they disallowed that, but your post has me wondering again.
anyway, sorry if my post caused more questions than answers