On YouTube, there are now a number of well done video's under the search term "Spontaneous Kriyas".
Before finding AYP, I was experiencing spontaneous kriyas. I did not know anyone else experiencing it when it began. My search to find others was long and exciting. It is new to see such movements on tape.
This man (at minute 2:30 and following, shows exactly the type of shaking movement that I experienced when on my back relaxing and allowing (if he had been on his side or standing, it would have looked very different):
This woman, shows the kind of upper body actions that could manifest if in a vertical position (in the phase when the shaking morphed into more smooth movements). The shoulder rotations were especially prominent in my experience:
These spontaneous movements were combined with intense ecstasy and witness consciousness. All yoga is a dialogue between the spontaneous and the willful. When I found AYP, I was aided in integrating the inner energies and outward manifestations into a daily practice.
I have the kriyas that the man was having often. Thank you for posting that. They are so full body and my head goes so violently back and forth, they frightened me at first. But then I got used to it.