I'm certain a poorly setup suspension could jar you around enough to hurt you but take into consideration there are a lot of other variables as well. Body posture has a lot to do with preventing injuries, that's why you are suppossed to ride in the "slumping" mode to protect your spine.Not landing a jump on the gas can cause even a works suspension to beat you up. It is like tossing a flat rock into a pond, if you simple throw it up in the air & let it drop, it'll plop right into the water. Take that same rock and put some angle on it and it'll skim accross the water almost like it's floating. Your bike & back is the same way, landing a jump off the gas and the bike will hit the ground hard, land it on the gas & the bike will skim right accross the ground. In either case your back needs to be bent so in the event you do land hard the disks don't slam into each other.