Did we mention that library stacks still exist? Not all information has migrated online.
Stacks, however, are tall and can be wobbly. Books, especially piles of them, can weigh a ton. Mix stacks and piles of books, and one not-too-in-shape librarian, and you get a recipe for:
Slip and fall
Fall and slip
Head injuries (ever had an entire top row of Fannie Farmer cookbooks fall right on top of you? No? Good. Keep it that way.)
Even sedentary librarians don't escape the strain of the physical world. Tap, tap, tap on computer keys means ouch, ouch, ouch for librarians who develop a case of repetitive stress injury. You could even develop some eye strain from staring fixedly at the computer screen.
And watch out for those chairs. Choosing the wrong chair today means an aching, twisted back tomorrow.