Orwell wrote:The worst thing I've ever done was pinching... something in my back. Not sure what it was, but anytime I did anything that used my upper back muscles there'd be a intense burn, like someone had taken a thick needle that they'd heated to hundreds of degrees, along with a sharp stabbing pain. I've been careful to avoid any activity that'd end in serious injury. Or just never enjoyed playing/working outside and did all I could to avoid it.
Sounds like possibly dislocating one of the vertebrae which pinched one of the spinal nerves. Yow! Nasty business, that. My mom was diagnosed 15 years ago with badly worn-out tissue that goes vertebrae, and told by her doctor to never lift anything more than 5lb or so... but the way she dealt with it was not by avoiding anything strenuous, but rather starting carefully directed exercise and switching diet. She's all clear nowadays, apparently that stuff regrows itself - IF you take proper care of yourself.
Now that I think of it, I may have broken a toe before, too, which went undiagnosed. My little toe on the left foot definitely has the wrong shape, and was a nice dark shade of blue for a month after I had a nasty run into a stair while wearing sandals (bloody things). It didn't hurt badly enough or inconvenience me severely enough to go to the doctor about it, but I suspect it probably did get broken and grew back together somewhat off-angle and became mostly immobile (can't move it much voluntarily). Doesn't bother me any, though.