If your knees hurt a lot when you stand all day for a job, check how you turn.
I do not know how people are supposed to turn, but given that the way I do it has been an unrealized source of pain, you can do it wrong.
I tend to let my leg stay on the ground for too long upon pivoting, leading to my femur twisting on top of my knee.
The solution I have found is spinning.
You spin on your heel, letting gravity carry you in the proper direction
It makes you look kinda like a weirdo and wears down your shoes faster but at least it doesn’t wear down your knee joint?