Hi Mark,
Thank you for your response, and I know what my struggles are in terms of anxiety. It's interesting that you claim it was 3-5 mph simply because I believe you were right if not a slight underestimate as I noted no damage to my vehicle.

I see so many people on this forum and otherwise claiming to be concussed after being rear-ended. If they are being rear-ended in low speed (10-15 mph) collisions, it just seems to follow that this event was of equal or greater force seeing that I hit a stationary object. Acceleration comes down to a change in velocity, and if you are moving in one direction, hit a stationary object, and are propelled in the opposite direction, it may prove similarly forceful as a one-way event such as a rear-end collision.

I am also not sure just how much cushioning a headrest performs, as you would have to be in contact with it for something like 100 milliseconds or more for it to substantially reduce force to the head.

I suppose those trains of thought aren't even relevant, but I am scared that an event similar to those that have caused concussions can have similar physical repercussions (i.e. a concussion).

You've had a lot a experience with concussions, Mark, so at what point did it just not matter to you if a blow to the head was a concussion or not? What made you indifferent (or whatever term you would use to describe your perspective)? You've clearly overcome concussion anxiety, but what allowed you to defeat that?

Tyler