I believe it's been called a body memory. This article I found today calls it something else, which is I think not coming from an expert but rather someone summarizing (read plagiarizing) the experts for personal gain and creating more useless life coaches (that's all we need :rolleyes:). Nonetheless, I found this summary to make more sense to me than some.
Maybe it will help.
I truly hate having this symptom. The first emotional response is to feel like a victim again, especially if it's painful. I do flashback management steps that cut dissociation that my T had taught me: cold (air, A/C, go outside in winter, drink cold or hot, or apply an ice pack), movement, and start doing something that requires focus/distraction, like cooking, gardening, or something that forces you to use ALL your senses at once. This is grounding. Best short cut is to smell Vicks or some strong smell which tells the parts of your brain that think you are back in the past trauma frozen in time that you are actually here in the present. It helps to notice the details in your environment and tell yourself what time you are in.
Resourcing – The Antidote for Traumatic Activation
The best part of the article for me was "The limbic, or emotion brain, and the reptile, or body brain, only remember in present moment. They don’t understand past or future like the neocortex does. It’s as though our bodies are reliving the experience, even though our cognitive brains are in the present reality."
My sister has these and used to think it was a ghost. It truly feels real. Hard to believe that the brain really doesn't know time has past.