Vascular Neck Restraints

Saturday, March 24th, 2012

The sleeper hold of pro wrestling is a legitimate submission move known to jiu-jitsu grapplers as the rear naked choke — because it doesn’t use the collar of the gi jacket — and to judoka as hadaka-jime (Japanese for naked choke).

In law-enforcement circles, it’s known as a lateral vascular neck restraint, and it has fallen out of favor, because it was blamed for a number of deaths. Now, a new study published in the Journal of Applied Physiology demonstrates what grapplers have known for a long, long time — chokes are safe and effective:

The results “demonstrate that the [only] important mechanism causing unconsciousness during VNR is decreased cerebral blood flow due to bilateral carotid artery compression,” the study team reports. Mitchell comments, “This did not come as a surprise. When the supply of blood-borne oxygen to the brain is cut off by at least 50%, the brain cannot sustain consciousness.”

Blood pressure, heart rate, and heart function were not adversely affected during or immediately after VNR application. A sensitive receptor located in the neck, which can send signals to the nervous system thereby evoking changes in heart rate and blood pressure, was not stimulated to an important physiological degree by the carotid compression, Mitchell says, despite speculative assertions about this in the past. Nor was there any evidence that blood vessels in the back of the neck were shut off during VNR, which some critics have speculated could ultimately cause the heart to stop. “Carotid compression did not threaten to produce a stroke or suffocation or create a near-death experience,” Hall observes. Vital signs for all participants continued normal after the carotid compression was released and they came to, the study found.

Respiration in some subjects was interrupted, “but apparently only because they voluntarily held their breath,” Mitchell says. No blockage of the airway could be detected.

Relatively little pressure is required to induce unconsciousness in most people with a properly applied and maintained VNR. “This is an important finding,” Mitchell says, “because even the smallest officers should have no trouble attaining and maintaining the minimal pressure required.”

Subjects with bigger necks and a higher BMI tend to reach the point of eye fixation leading to unconsciousness more quickly — “important street information,” Mitchell says, “that confirms anecdotal reports from trainers and officers.” The reason is unclear, although he guesses that these people “may have more tissue that can be used to compress the vascular system with the same amount of pressure.”

When the technique works, it works fast. Mitchell advises: “If you are applying and holding the VNR properly and the resister is not going out after 11 to 13 seconds, the technique is probably not going to work and you should transition to another force option.”

A proper VNR inflicts only mild discomfort, but as the tap-outs during the research confirmed some subjects readily submit once the hold is in place because they sense what’s coming and they don’t want to experience unconsciousness. Butler says this is frequently the case in actual street encounters.

Leave a Reply