Yes - that's right. Usually it means twist someones arm behind their back. I am sure you have seen this - very much a favourite of security services worldwide. It means they are in control and you must do what they say.

We also say, "go on then, twist my rubber arm". Which means you are doing something you want to do, but pretending that you don't. Like - people at work saying, "Craig come to the pub after work" - and I say, "Oh go on then, twist my rubber arm". It's strange how we pretend not to like something, when we really do. English people are strange - people are strange. (the last place I'd want to be after working, is in a pub with the people I just spent all week with) (really - I mean it haha)

Come to me and I'll explain you =D ...heheeeeeee =P I'm told it's not an idiom ;)

to twist someone's arm - figuratively speaking - means to persuade or convince someone to do something

Have you been twisting Shalit's arm?