Monday, June 4, 2012

The Case of Preston Hughes III: Shime-Waza

From Principles of Judo Choking Techniques: "Different Chokes for Different Folks"
Shime means constriction and waza means technique so this group of techniques are all those involving constriction. ... Compression of the carotid arteries is desirable because it requires the least force, is the quickest acting of the choking techniques, is the most universally effective against all opponents, and it is most in keeping with the efficiency principle of Judo, "maximum effect with minimum effort." ... A good strangulation hold should render the opponent unconsciousness without injury or significant pain in a matter of seconds regardless of whom the opponent is.
The "choke holds" known as shime-waza used in the sport of judo have been taught and used by law enforcement officers to subdue violent suspects. ... If the carotid artery hold is properly applied, unconsciousness occurs in approximately 10 seconds (8-14 seconds). ... [T]he amount of pressure directed to the superior carotid triangle needs to be no more than 300 mm Hg to cause unconsciousness in an adult. A female can, if the choke is properly performed, without great strength "choke out" a male twice her size. The state of unconsciousness ... is caused by a temporary hypoxic condition of the cerebral cortex. ... It has been confirmed that complete obstruction of blood flow to the brain ... will result in irreversible damage to the body which often results in death. While unconsciousness (ochi) caused by choking (shime) in judo is a temporary reaction which incapacitates the opponent for a short while, its execution is quite harmless.
Judo has been around for 130 years. From more than a century, judoka (those who practice judo) have known that a human can be rapidly rendered unconscious by preventing blood flow to the brain via the carotid arteries. If both common carotids are constricted, unconsciousness occurs within 8 to 14 seconds.

In Silence of the Lambs, I presented experimental evidence that a sheep's brain becomes unresponsive in 14 seconds if both carotid arteries and both jugular veins are severed. That's remarkably close to the 8-14 second time-of-consciousness for humans after properly applied shime-waza.

In Where's Willis, I presented evidence that sheep and humans have nearly identical blood volumes and cardiac outputs. Based on this post and the two just referenced, it is clear that sheep provide a good analogue for studies of time-of-consciousness after restriction (or diversion) of cardiac arterial flow. When sheep have their carotid and jugular severed on one side only, as did Shandra Charles, then sheep lose brain function in 70 seconds, on average.

There is no reasonable chance that Shandra Charles remained conscious more than 90 seconds after her left common carotid artery was "transected" (completely severed) by a double-edge blade. It is therefore impossible that Shandra Charles provided a dying declaration to Sgt Hamilton who arrived on the seen no more quickly than 10 minutes after the attack.

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