I asked myself the same thing the other day when my back "went out" bending over to tie a bag of garbage....my solid answer...NO!..it does not exist...how many times do I bend over in a day? like 10000 times-this one time I bend over to tie garbage and my back goes out?so all the times I bend over to pick up engine blocks--no troubles---but a bag of garbage does me in? in my case something else is going on mentally---like my wifes ovarian cancer scare