I haven't had this happen in therapy,....but I thought I'd reply anyway. I'm sure it could happen.

I have had this happen outside of T. When I was little, I had the most god-awful panic attacks. I'd cry, shake uncontrollably and violently, ect. They were horrible. Anyway, it was just the extreme anxiety and fear.

But I've also had it happen in other circumstances, where I wasn't feeling the anxiety or panic. This was hard for me to understand. Without saying the event that caused this, it had happened an hour or two prior. I had to go to the hospital, and I basically could hardly stay on the bed from shaking so uncontrollably. I thought, "What in the world??"

Anyway. My T specializes in trauma, and she often gives me examples and tells stories to make her points. She once gave an example of a sort of "delayed fear/trauma reaction," where after going through an extremely traumatic event, your body can release the fear this way, in uncontrollable shaking or movements. I can't explain it nearly as well as she did, so I don't even try or I'd mess it up. She used a polar bear in the example, but it made sense to me after I'd experienced the violent shaking a few times.