Monetary deflation is only a problem in a banking system where new money is created from credit and the math requires an increasing number of loans to pay interest or else someone must default. It is perfectly stable when money is not debt and its existence does not depend upon paying someone interest.
In order to fall far enough to break your neck, you need something to propel you up that high in the first place. Fractional reserve + legal tender + money inflation is a good way of doing that, but credit based on real savings in a free market would find it much harder to do so. The people so scared of monetary deflation forget that a great inflationary expansion must occur before there can be a deflation!