Rick T
When I am awake the tremor stops. Once I started with the whole body tremor the problem with my foot seemed to stop. The single tremor was violent enough to wake me and my wife up. I could get back to sleep only to have it happen again. It happened about 6 times during the night.
Anxiety and Stress
Either you are having bad dreams where you suddenly need to do a sharp jerky action or maybe you need to see a doctor