I played ice hockey with a NY State Sheriff who was on medical leave for supposedly injuring his back during an on-the-job car pursuit and accident. He looked OK to me.
Not that he might not be exaggerating his problem, but bad backs are funny things. I wouldn’t have known that until I developed a bad back problem myself from lifting things repetitively that were very heavy on one job I had for a few years. I have to have back support now when I’m sitting and sleeping, and I have to be very careful how I pick things up, too. But other than that, I can still do a lot of physical things normally.