Brewer's Finger
It's bad enough I can't stretch my elbow out straight... but who needs a piece of sandpaper on their index finger? I can't say I wasn't warned though... Vince showed me his (um, brewer's finger) within days of my starting work at the brewery.
Its origin is the clamps we use to hook hoses onto the kettle, filter, fermenter and cleaning equipment. Some of them are smoother than others, but all require a judicious amount of torque to get everything sealed up properly.. and there's the "rub."
The smooth clamps only give you carpal tunnel... the rough ones... THEY give you "Brewer's Finger!" Feel to ask about rubbing any of our fingers next time you're here on tour... I hear it's good luck!