Expert: Alan Kahn - 3/3/2006

Question
What is it exactly that causes some one to be knocked out? What physically goes on to cause it?

I know this is probably not one of your usual questions but im doing a school report on mixed martial arts. im trying to figure this out.

thanks a lot    

Answer
Hi John

Actually, your question is a very good one. Quite difficult to pin down, and I spent a long time researching this. Here are some interesting results. ( and you can click * "related links" on the right hand side of any pubmed article to find more related reports"
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A Knockout in boxing entails deliberate production of the state of unconsciousness.  See:
Acute subdural hematoma caused by professional boxing
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstra...

and it appears to be from a "Transient unconsciousness" with or without concussion. Others believe a knockout would also entail mild concussion http://nanonline.org/nandistance/mtbi/modules/sports/dings.html

and here:

** Concussion: comparison of humans and rats
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstra...

( Concussion is the most primitive and probably the most simple central nervous system response to an outside agent. Although millions of neurons undergo a very rapid reversal with loss and restoration of function, many physicians argue that every knockout blow leaves some residual damage, i.e., some or all of these neurons stop short of recovery...)

this seems to lead to a new view of "knockout" (unconsciousness for short period of time) as a "CHIT" or closed head injury of transient type. http://www.pni.org/neuropsychiatry/chit/classification.html
The definition listed states "little or no unconsciousness, or and alteration of consciousness that does not last longer than a day".  Most boxing knockouts do not leave the boxer completely unconscious, carried out cold on a stretcher, but rather have the man incapacity neurologically for a brief period, often less than 2 or 3 minutes. This loss of function is most likely described above as a rapid reversal of activity, but exactly what that means is hard to pin down. I would say it certainly qualifies for a Grade 1 Concussion,as described here under Head trauma: http://en.wikipedia.org/wiki/Head_trauma

There is a lot of related medical literature on the topic of boxing, martial arts and high velocity sports concussions or brain injury. Most of them tend to focus on the long term effects of repetitive trauma, but on your more immediate focus there is some findings.  

Neurological and CT evaluation of knocked-out boxers.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstra...

Duration of cognitive impairment after sports concussion.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstra...

neurologist's reflections on boxing. V. Conclude remarks.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstra...

On-field predictors of neuropsychological and symptom deficit following sports-related concussion
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstra...

You might also find these interesting concerning martial arts

Video analysis of head blows leading to concussion in competition Taekwondo.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstra...

Video analysis of blows to the head and face at the 1999 World Taekwondo Championships
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstra...

Punch drunk syndrome due to repeated karate kicks and punches
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstra...

Head and neck injuries in young taekwondo athletes.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstra...

Martial arts injury overview
http://www.sportsinjurybulletin.com/archive/martial-arts.html

I hope some of these links and articles help you on your school report.

sincerely,

Alan Kahn
author, The Speed Bag Bible
http://www.putfile.com/speedbag