Explanation: This is a metaphor for people who play the principal role of a backbone or the key figure.

Ex.:Xiao Zhou hasn't been to college, but he studied assiduously by himself and became the backbone technician of the factory, or the key figure in profession, as everyone says.

Explanation: Make things difficult for somebody by deliberately doing the very opposite of what he is doing.

Ex.: I don't think you should do that against your boss. It won’t do you or the company any good.