That's how I'm now disabled, and full of osteoarthritis.
I used to shift 14ft RSJs by myself. lol I was a human wrecking ball. Yes and it was great fun, and yes, I did knock myself out more than a couple times! Oops
Once, when transforming a sprinter van into a minibus, I passed out... I forgot to leave the windows open, as I glued down the carpeting! Hehehe one of the worst headaches ever