Hey pusher were did you get this information?I would say the chances of a fractured vertabrae are very slim.
An mri will not tell you everything,most doctors dont put you through the expense of one unless they really think you have a serious problem.Over 90% of back problems are from muscle+tight hamstrings can definitely give you back problems,so can strained ligaments.
I have read that tension can cause back problems,a lot of people have back problems+thier mri shows nothing wrong.The back is still a mystery in a lot of ways to modern medicine.
I use to have back problems+still once in a while i have some but since i started doing stretches that are specific to my muscle imbalance i have been pretty much pain free.
There is a lot more evidence that muscle imbalance causes a lot of injurys, I bought a program called lose the back pain +thier claim is that imbalance in the muscles is were the problem lies.
I can tell you first hand that i went to quackropractors+it didnt work,doctors would give me anti inflamatorys which would help me get rid of it but i would have a flair up every 3-4 months.
After doing the excersizes+stretches to correct the muscle imbalance i have been almost pain free.
Once in a while i have a mild flair up which is usually from not doing excersizes regular, sitting to long with bad posture, not warming up well enough or sleeping in + then sitting instead of doing some walking to loosen up.
I am 50 years old+ play tennis 6 days a week without the lose the back pain program i would not be playing like this!!