Sorry it's that time of the month again where my questions are filling up the front page, but this one just caught my mind. I think each and every one of us have leaned up against a wall either standing/sitting waiting or whatever reason we do it for. Anyways, if we decide to relax our head by leaning the head up the wall, which I guess most of us do if having to sit for a long time, I was wondering if the small impact with your head on the wall can cause a sub concussive blow? Because sometimes you can hear people making a bump sound, I even had it happen to myself today, so that's why I'm asking. I get all dizzy if I do it too roughly, so this worries me, but then again, time and time again has proven a lot of things that doesn't mean anything end up making me dizzy, no matter how much I try to ignore the fear. I guess it's my subconsciousness keeping my anxiety going or something. Anyways, my scenario was I was watching a movie and needed something to lean on, which ended up being the wall. So my head came in contact with the wall doing that bump sound and a shaking of the skull. I guess my head bumped into the wall with a 2-4 cm distance.

It might be a silly question since I see it happen to people occasionally without complains, but I've been wondering about this, if it has a sub concussive potential or something?