You have probably read some have no problems with the vest and others do, including me. I started having a sensation on on lower left side just above my waist. I quit using it.
I think it can cause new problems for some, that's how it was for me. I believe it can irritate existing problems etc. I think it is working and pumping in areas that are not necessary to be worked. I found my way to doing my own "percussion clapping" on my chest/lungs on either side of the breast bone and 'fist hammering' comfortably on my lungs at my back and sides on either side of the spine. I believe it does satisfy what is needed. So with doing that along with nebulizing, Active Cycling Breathing Technique etc. I am moving the mucus out. I realize some can do it all and not feel they are accomplishing much.
I sent the vest back and they are to credit Medicare and my Supplement Plan for the period I was not using it before returning it. I was told to let Hill Rom/Baxter know ASAP when I stopped using it in order to return it and credit the insurances. The only problem is if you feel you might want it again and you return it Medicare may or may not approve it again.
Hope you find your way so that you don't have the sciatica flares.
Barbara