Good ol' carpel tunnel and repetitive motion - hammer use, typing, slamming wrenches with your hand, tile workers, wood shop folks - gonna eventually do a job on your hand and wrist. I'm thinking that air impact tools are a mechanics biggest enemy. I don't use mine often, but my hands are just plain sore after a session with the 1/2 drive air impact wrench or even that light duty 3/8 drive air ratchet. My wife who is small boned had both hands done in an earlier life - now has weak hands to the point they ache if she does much manual work. Me - so far just have a couple fingers that lock occasionally, along with a thumb that has a bad joint.
IT'S H3!! GETTING TO BE AN O.F.