The worst of the bumps are harder on my spine than the boxes and the stops. Some places here in the south are in terrible shape. Should be ATV-only.
It was always shoulders, rotator cuffs, and knees that bothered me, and I didn't even do the job for that long. I think some people just win the genetic lottery with body durability.... and some people just aren't made for it even if they follow the methods.
When it comes to my back, I bobtailed over 200 miles in an old Sterling a few weeks ago and woke up pretty tight the next day..... it's a tough job but somebody's gotta do it.