Hi and welcome to the Chiari forum.
We do have a list of activities to avoid with Chiari and Syringomyelia in the Health Pages here is a link to the pages, u may find more info including a list of Drs and tips in there as well as that list.-
http://www.medhelp.org/health_pages/list?cid=186
U have to listen to ur body as to what u need to avoid as we will all be affected differently as it is possible to have other related conditions, so instead of looking for a NL,. u may want to locate a Chiari specialist that can help with the testing u should have done next to see what else is going on.
Did the Dr that DX'd u do testing for CSF flow? Look for a syrinx? tethered cord? ICP, POTS, Ehlers-Danlos?