Fig. to pressure someone. (Fig. on the image of hurting someone until they agree to cooperate.) I had to twist her arm a little, but she agreed. Do I have to twist your arm, or will you cooperate?
to persuade someone to do something that they do not want to do He might help us with the painting if you twist his arm. (humorous) 'Have a cream cake?' 'Oh, go on then, if you twist my arm.'