I don't think there is an answer to your question. Side to side, front to back, up and down, they all have movements but unless you did them continuously for many many repetitions, I doubt they would make any difference. I have told you this previously. Sub-concussive impacts cause damage when there are hundreds of them over a relatively short period of time

You are asking hypothetical questions that do not seem to have a legitimate purpose. Are you planning on an activity where you would need to repetitively move your head back and forth in any of these directions ?

Tearing axons is not the only way a concussion manifests. Plus, axon shearing is not necessarily an immediate event. The axons can be strained resulting in slow deterioration. You said "Or is the odds of tearing axons greater with up/down movement? I recall that's been said." I don't recall anything like that.

Nobody is going to test somebody by having them move their head repeatedly to see if it causes any damage. The only live concussion testing done is done on rats. The research done with football players is not accurate enough to pinpoint the difference between concussions caused by different directions of force.

Are you getting any serious counseling for your OCD ? You really need somebody to help you let go of these concerns. I don't think any amount of factual information is going to change your OCD regarding this. Your mind will continue to find a new way to obsess about these issues.

So just to be clear, the internal weird feeling as if my brain slams into the skull is just an illusion of some sort? To describe it, it's in a way the same tingling feeling I got from fast side to side movement, now it's just coming from up and down movement instead. An earlier comment of yours in this thread just seem to mention that repetitive forward and backward movement of the head seemed to cause cumulative trauma and so this worries me since I believe it then poses a greater risk of injury than that of turning the head side to side. So the weird sensation you get for example from nodding your head fast is harmless? If it's even normal to feel what I'm talking about? Can it be the body's sensory defense system warning me to slow down before it actually causes any damage or something? Even when I'm nodding, all it takes is doing it a bit fast with followed by a sudden stop and then for a very short duration of time, I can feel some sort of internal pressure, hopefully just because it's provoking blood circulation. I also just kinda wanna know if you most likely would pass out from shaking your head before trauma occurs? Or would your neck get severely damaged? To summarize, I'm hoping that the answer is the body's natural response activating some cautionary mechanism and not actually movement of the brain I can feel either inside or outside my head, can't tell.

I don't think any of what you have said as the basis for your worries have any validity. "An earlier comment of yours in this thread just seem to mention that repetitive forward and backward movement of the head seemed to cause cumulative trauma and so this worries me since I believe it then poses a greater risk of injury than that of turning the head side to side. " I did not say that repetitive forward and backward movement can cause damage.

If you spend a few minutes vigorously shaking your head front to back, up and down or side to side, it could cause concussion like symptoms. But, I know you would never do that.

I bet the responses you are feeling have more to do with the inner ear.

Small momentary changes in blood pressure to the head and face are common as the blood vessels respond to different head positions. This happens with everybody. It is not a response to protect against damage. It is a response to keep adequate blood flow so one does not pass out from lack of blood flow.

So, yes, that weird sensation is harmless.

You really need to find somebody to help you let go of these worries so you can get on with living your life.

Alright so you would basically have to do it non stop constantly for minutes. And even then, concussion like symptoms occurring doesn't necessarily mean an actual concussion has happened? Rather a severe disturbance of blood flow or inner ear?

Nobody said anything about a severe disturbance of blood flow. More likely a common but momentary change in blood flow.

Minimac, you're most definitely allowing your anxiety/obsession to take hold, and I'm confident that this worrying poses a far greater risk to your health than anything that you have done with your head as of late. Trust me; I've been trying to get over the very same mental obstacle for the past year, and I'm still not quite there yet.

For example, a part of me still thinks that I'm experiencing concussion symptoms as a result of a particularly "vigorous" activity from earlier this week... I don't quite know how to say it on this forum, but yeah. Sure, it caused my head to jerk around a bit, and—even despite the fact that I've had far too many alcohol-related concussions within a very short timespan (recently, too)—I have to keep telling myself that I'm fine.

As of this past pseudo-incident, hitting the books intensely for a few hours will cause me to feel a pressure sensation in my head, but I'm able to make it disappear instantly by simply relaxing my cranio-facial muscles. Now and then I'll notice what seems to be tinnitus—no, now and then I'll resolutely convince myself that I'm experiencing this hallmark symptom of concussion, but then I tell myself that I've always heard this noise, that even my healthy brain had regularly perceived this kind of sound.

You'll be fine. People keep on learnin', world keeps on turnin'. You're ten years post-concussion, and you've only had one...I remember hitting my head pretty hard only 10 or so months after my initial concussion as a kid, and I was fine. In fact, before my more recent "set" of alcohol-related concussions, I busted up my teeth (and my face) on some ice without cognitive deficit.

Persistence is great in the pursuit of knowledge, and I'd encourage you to go explore the scientific literature ad nauseam (if that's your thing), but obsession and incessant self-projection will eat you alive.

Cheers!

Yesterday evening, I had a really strange experience. I walked pretty fast through an open door, because my food was ready. I wasn't catious enough due to beein in a hurry and snaged with my left under arm on the left door frame. This resulted in a very fast turn of about 90 degrees of my whole body. The head itself did not move the full 90 degrees, because of the necks rotational ability(I hope you know what I mean here).

In conclusion, this incident resulted in extreme fatigueness a few minutes after it happened. I was so tired that I fell asleep. Today I'm still a bit dizzy. Actually, I have no explanation of this. I also don't know wether this can be called a subconcussive impact, as the head itself didn't hit anywhere.