This is purely to stop you sueing the company if you fall off the ladder.
Suppose you fall off a ladder at work. You say you have never been trained how to climb a ladder and you sue the company.
So now companies train you to do all sorts of simple things, then get you to sign a piece of paper to SAY you have been trained.
Now you are in no position to sue the company as they can prove you have been trained.
It is all the fault of those "no win no fee" shyster lawyers, so if you are going to blame anyone blame them.