I was lucky enough to break my neck in 1976 which changed my fiddle playing completely. I say lucky because I stopped gripping the thing with my chin and let it sit down on my collar bone. At the time I thought this was unique but I've since seen photos of Neil Gow playing like that. The first improvement was that I could sing while I was playing without sounding like I was being strangled. The second was that everything became a little looser which would have been hopeless in classical playing but suited the fiddle style well. Later on, I found I could even call the dance steps at the same time as playing. So in retrospect, if you're going to play violin style and tuck it under your chin, your long-term health will benefit from a shoulder and chin rest, but trying other ways can be fun.