Yes that is what i mean by a hypnic jerk. When sleep paralysis takes over, it starts at my feet and the last place it gets to is my head. when it gets to my head, you know how people experience the falling sensation or the feeling like someone is shaking the shit out of them? This is usually accompanied by HH right before the dream. This is when i usually spasm or hypnic jerk out of paralysis. That's what i mean....spasm = hypnic jerk.