Ridecamp: [RC] Body protectors

I suffered a fairly severe spinal fracture this summer in a  riding fall. Horse spooked, did a fast 180 spin that I was not at all ready for, and landed on my back. I purchased a body jacket for next spring. (Hopefully my post traumatic stress will be reduced by then). I purchased the one with the highest protection. It's like wearing a vest made from thick plywood, plus it says on the package insert that it does not protect against, torsion injuries, spinal injuries, etc., etc. What exactly are they good for? I was hoping that this vest would prevent or minimize trauma to my back in a fall but I'm not sure if it prevents against a lot of anything. Would appreciate any feedback. 
Deb