This reminds me of some of the things a friend has described while doing a certain type of physical therapy session. She decided a while ago to post openly about her ptsd and experiences in case it would help anyone (warning; read her cut tag warnings if you have triggers) and even though in a way this is off topic, I thought you might be interested in her descriptions. Edited to add: I found her first post on EMDR, which explains it some: http://sheafrotherdon.livejournal.com/506950.html Here are her posts tagged ptsd: http://sheafrotherdon.livejournal.com/tag/ptsd I believe the type of therapy she has been trying is called EMDR? And it involves recognizing how one's physical body stores/recalls trauma even when the conscious memory does not. That is what reminded me of your experience, so I thought it might possibly be helpful, though definitely it could just be a "regular" yoga reaction.