I think there is also a difference between PCS /concussion and a TBI injury...

A concussion is a subset of a TBI but it would still take a strong fist hit to cause a concussion. A simple example would be. If you could pound a nail with your finger tip, that finger could possibly cause a sub-concussive impact. A finger just does not have enough strength or mass to cause such an impact force.

Thanks for the replies I meant getting a concussion from doing this not a serious tbi. Ever since I've had concussions I get very worried on how much of a impact can cause a concussion. Because I know sometimes the slightest bump can cause one. And I always thought the temple was a spot were if you touch or pressed on or in my case tapped it could cause a concussion.

Pretty sure it would to be an actual bump , like a fall, hit or bumping hard with your head into something equally solid..
not a finger or most body parts which are somewhat padded..

That re- injury scenario probably applies more to those that go into risky activities or back into contact sports..
That is the reason it is mentioned , for those asking about getting back to those sorts of activities.

Thanks again for the replies I hit my head five days ago when I was underneath a wooden table, i didnt realize I was still all the way under and it hit the top of my head hard and caused a concussion,my second in two months while still having lingering pcs. This concussion has left me really dizzy and out of it its only been five days but I worry with such a close time frame between a car trunk slamming into my head, hitting my head on a bed post and now hitting my head on a wooden table, how actual recovery will be. Thank you for the replies.

"And I always thought the temple was a spot were if you touch or pressed on or in my case tapped it could cause a concussion. "

A concussion is a severe shaking of the brain matter inside the skull. If the skull is not moved violently, there is no shaking of the brain matter.

The temple is plenty strong. Touching or pressing on the temple or any other part of the skull will not cause any kind of injury to the skull or the brain inside the skull. I doubt you could even bruise the skin unless you nicked the skin with your fingernail.

You can put more pressure against the skull by pressing than you can by tapping. Pushing is a continuous muscle force. Tapping is a momentary force. The muscles used for a tapping action are very small. The mass of the finger is very small so there is minimal energy transmitted to the skull.

It takes about 10 G's for the brain to even sense an impact. That would be like your finger lifting 80 pounds at its tip. One finger can barely lift 8 pounds without risking damage to that finger or the tendons.

The minimum threshold for a concussion is believed to be 50 to 60 G's. Many can tolerate well over 100 G's without suffering a concussion.

Not everyone who has a concussion ends up with Post Concussion Syndrome.

A concussion is one form of Traumatic Brain Injury.

Sometimes called TBI, sometimes called mTBI and in some places I've come across in Au it's just called a head injury. Like PCS, the symptoms and severity differ greatly.

One does not need to have a penetrating injury to the brain to have TBI.

http://www.nlm.nih.gov/medlineplus/t...aininjury.html

Yes, I was wanted to clarify because of this line by bmkp13.

[How much force with a finger could cause a tbi ]

Basically a finger tap or poke could not cause such an injury.

Mark after reading some of your posts you seem to know a lot about concussions that are close together like 2 or 3 in a 3 month period, is that called multiple impact syndrome? I've had 4 concussions in my life but 3 were really close in time frame, is there chance for healing?

Yes, there is a good chance for healing. I've had 14 concussions over 36 years. Only my last caused life changing problems. Some of the others cause prolonged symptoms but I was able to get on with my life.