I only shake when I'm at work and I'm trying to be assertive. My abuser was my supervisor at three jobs over the course of 6 years. If I try to assert myself to my current supervisor (who is unaware of my experiences) regarding company policies, employment law, etc., and they dismiss what I have to say, I start shaking, but I'm not sure if it's external or just internal. It definitely gives me the jitters and makes my throat swell up, though. The last time my boss challenged my request, I raised my voice and told him he needs to respect his employees and respect company policy and the law. He argued that the spirit of the law was more important than the letter of the law. I said that the spirit of the law is to respect employees, and that he wasn't doing that. I told him very forcefully that I demand his respect, and that it requires him to follow the letter of the law when he's around me. He said okay and walked off. I felt pretty good. :)