Couple of years ago I read in the medical literature a report from a bunch
of scientific wackos who hooked up judoka to heart monitors and EEG equipment,
then had them choked out by their sempai. The monitors showed that blood flow
to the brain is indeed momentarily interrupted (surprise, surprise) and that
there are temporary EEG abnormalities while unconscious, but that full
recovery occurred after each choke. One fellow was willing to be choked out
five times for Science and each time he had the same level of function that he
had before (of course, you gotta wonder what's the baseline for a person who
is willing to be repeatedly choked unconscious for Science?).
The forensic literature says that if you are going to kill a person by
interrupting blood flow to their brain, you need to hold pressure for minimum
two minutes. How they got this information I do not know. People have been
convicted of murder based on it, because having to hold pressure for two solid
minutes is good evidence of intent. Reversing this, it would suggest that if
your friend chokes you out and lets go as you hit the mat, you ought to
recover fully just as the judoka in the experiment recovered fully.
However, interrupting blood flow to the brain is not the only way to
cause death. There are two other methods with which you should be concerned.
One is bradycardia and arrhythmia based on carotid sinus stimulation, and the
other is positional asphyxia.
The bradycardia one means that if you're choking just the right spot very
high and fairly lateral on the neck, up behind the sternocleidomastoid muscle
and only an inch lower than the jawbone, you may accidentally put your thumb
on the sensor located in the wall of the carotid where it divides into
internal and external branches. That sensor is there to tell the heart to slow
down if the blood pressure going into the brain is too high. If you push hard
enough on the vessel and up the pressure in it, the sensor tells the heart,
"Whoa! We gotta surge of 80 mm Hg in here! Back it off!" And the heart
obediently slows down to nothing, at which point it can start to fibrillate
and you die. The reason this is rare is dual. Number one, the sensor is small
and hard to get to, so it's chance if you happen to be over it. Number two,
young people with resilient arteries are almost all resistant to this reaction
to carotid compression. Old people with hardened arteries are much more
susceptible. However, this has been thought to be the genesis of death in
cases in which the perpetrator confessed, "I was mad at her, yeah, and I took
her throat in my hands, but honest to God I didn't do anything! She just went
limp the instant I touched her!" and the autopsy is negative. So this is
always something to bear in the back of your mind when practicing chokes: if
your partner is the one in a thousand whose arteries aren't resistant to this,
and if you hit exactly the right spot, they could go limp in your hands and
die without your even achieving a good choke. Scary.
Positional asphyxia is likelier because one tries to get it in judo. If
you're on his diaphragm so he can't breathe, and you choke him, and you hold
it too long, he might die. Again, if your choke lasts only a second or three,
this is unlikely. It is much likelier if he is hog-tied or even merely face
down. I would never practice chokes with a face-down opponent.
Tracheal compression is less worrisome to me, even though an element of it
is present in most judo chokes (correct me if I mean strangles -- I'm not a
judoka), simply because it takes so much effort to do it enough to flatten the
C-shaped trachea. And you'd have to really flatten the trachea to prevent any
air at all from going back and forth. I have been told it can be done easily
from behind with a nightstick, but I have never seen it done from the front or
back with hands alone; if you get your hands, or his collar, into good
tracheal compression position, you're probably pressing on his jugulars and
carotids too, and he'll go out from those long before you significantly
flatten his airway. A good thing -- the vessels recover completely from being
pressed flat; the airway gets damaged, and it can swell up and choke off air
flow minutes to hours later. If any of you has access to Spitz and Fisher
ed.iii (the $190 volume that's the bible of the forensic pathologist), on p.
447 Spitz says: "It is said that five pounds of pressure per square inch
suffice to occlude the carotid arteries and jugular veins. Thirty-two pounds
are required to block the airway." And later, on p. 448 he goes on: "Actual
compression of the airway by the noose in hanging cases is not as common as is
generally believed. Supportive evidence for this includes the finding of
vomitus in the airway of numerous hanging victims. Sucidal hanging by persons
with an artificial opening into their airway (tracheostomy) below the level of
the noose also illustrates this point. Such individuals continue to breathe
while dying" (presumably, of jugular/carotid compression). "Obstruction of the
airway usually elicits a struggle, a dramatic condition known as air hunger.
... Judging from the circumstances in which [jugular/carotid compressed]
individuals are found, there is certainly no indication that this is an
*unpleasant* mode of death." (Emphasis his.) So if you're gonna choke 'em out,
and you wanna be nice, or you don't want to elicit struggle, seems like you
would go for the five-pound vessels rather than the thirty-two-pound airway.
Unless you're old-style LAPD.
He also quotes Reay and Eisele's fascinating 1983 article in the American
Journal of Forensic Pathology, "Death from law enforcement neck holds," to say
that in the judo-derived police carotid sleeper hold, "blood flow to the head
is reduced by an average of 85% in approximately six seconds... Despite the
apparent harmlessness of the carotid sleeper hold, occasional deaths do
occur... Movement during a struggle may turn a sleeper hold into a choke hold
with serious, even fatal, consequences", which I think was Ken's point.
I grant you that there is a midpoint between no harm and death called
brain damage, but, Ken, I have never seen a successful suicidal hanging
resuscitation that ended up brain damaged, only fully resuscitated or dead. Of
course I do not know the literature on this point.