While practicing, my body will sometimes involuntarily jerk enough to snap my head back. I then just come back to the practice. It seems to occur with Anatta insights. It seems like a quick jolt of energy sometimes.

What is happening?

Background on my practice. I sit an hour and half in the morning 30 minutes or so at night. I practice jhana (up to seventh or so) goenka style vipassasa (up to equanimity of formations). No stream entry yet.

Not sure but could be some kind of "kriya" phenomena. Search for kriya or spontaneous movements and you'll find a lot of info on the internet.

Hey R Aaron,

Personally, when my head "snaps back" its because I've nodded-off during the meditation But there are other reasons why your head could be moving around unpredictably in an "energy jolt" sort of way. In the MCTB these sorts of phenomena are often discussed in the context of the A&P.

What are your meditations sessions like (painful, distracted, calm, full of visions, focused, etc.)?