Oooh ooh I know I know
I'e been studying and working with them for some time now as a pranic healer, which is all about chakra alignment/clearing/energizing.
Different chakra misalignments lead to different pathologies, and pathologies can be interpreted through the health of various chakras. Chakras are actual biological realities, as they're situated along the nerve plexuses of the spine, meridians and organs.
I talk a bit about chakras on my blog: www.threecupsoftao.blogspot.com
(it's a work in progress).
Barbara Brennan's books are *excellent*. We use them in class.