text: when your arm feel funny? my arm fell like shake and could not stop it did you feel any cramping at all? sometimes this can happen from cramping, otherwise spasticity (muscle spasms) tends to affects larger areas of the body - arm, leg, trunk, neck.. which is what it sounds like you had/have. here is a little information on muscle spasms in this is the case.  http://www.alsa-or.org/treatment/musclespasms.htm  as for what fuschiahedgehog said above that is just absurd to say "could be anything from a seizure to a stroke" who seems to think they are a doctor. ridiculous! here are the signs of a stroke to better educate yourself... i can almost see "seizure" because epilepsy causes muscle spasms/seizures which can cause an arm to shake out of control, but usually there are more signs of a seizure than just that: http://www.americanheart.org/presenter.jhtml?identifier=4742   anyways, you are better off seeing a doctor other than reading what others have to say who have no medical background.  edit: from reading all of your questions i would strongly suggest you see a doctor right away... fever and involuntary jerking/shaking can be a danger and something has to be causing it. if insurance is a problem, there should be some form of clinic near you that can work with you.. also an er in a hospital can't turn you away and won't charge you on the spot.. usually they will work out some sort of payment plan as well.