I think entry #4 and #17 are very professional and I like the AE you have created, however, I would like to a spine implemented into both designs and the word "chiropractic" in #17.
Entry #3 initially caught my eye, however, I would like to see the design on the left changed to more of a spine rather than a figure. It kind of appears as a person dancing and I would like something a bit more sporty.
Entry #2 is my least favorite of your submissions. I feel there are too many colors and that, while nice, this design would be more appropriate for a pediatric practice.