Chokes research

Although, during training or in completion, it is near impossible to choke/strangle a person to death (used in Judo since 1882, no deaths have been attributed to their use), there are other ways the person may die. One way is bradycardia and arrhythmia based on carotid sinus stimulation, and the other way is positional asphyxia. The bradycardia way means that if you are pressing at 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 tells 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 suddenly increase the pressure in it, the sensor tells the heart to slow down, and the heart obediently slows down to almost 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 difficult to reach, so it is 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. Older people with hardened arteries are much more susceptible. Positional asphyxia may happen when grappling. If you are pressing on the opponent's diaphragm with your body weight while applying a choke, then he or she will not be able to breathe. They will not be able to initiate a breath. If opponent is face down, it may also occur.

According to Spitz and Fisher (the bible of the forensic pathologist), five pounds of pressure per square inch are sufficient to occlude the carotid arteries and jugular veins. Thirty-two pounds are required to block the airway. Therefore, it is easier to strangle than to choke. In the case of hangings, death usually comes not from compression of the airway by the noose (choking), as evidenced by finding vomitus in the airway of numerous hanging victims, but by jugular/carotid compression. Obstruction of the airway usually elicits a violent struggle, a dramatic condition known as "air hunger." However, judging from the circumstances in which jugular/carotid compressed individuals are found, there is no indication that this is an unpleasant mode of death.

Considerable scientific research has been done by the Japanese and published in two reports of the Bulletin of the Association for Scientific Studies on Judo, Kodokan, in 1958 and 1963. The following are some of the conclusions made based on their experiments.

• Unconsciousness occurs approximately 10 seconds (8-14 seconds) after choking. After release from the chokehold, the subject regains consciousness naturally (spontaneously) without difficulty in 10-20 seconds.
• Pressure on the larynx and trachea produced excruciating pain but there was no pain in other techniques before unconsciousness.
• The unconsciousness resulting from choking is mainly due to lack of oxygen and metabolic disturbances created in the brain, as a result of disturbance of cerebral circulation.
• The appearance of flushing of the face is due to disturbance in pressure in the carotid arteries and jugular veins.
• Tachycardia (increased heart rate), hypertension (increased blood pressure), and mydriasis (dilation of the pupils) were caused by stimulation of the sympathetic nervous system (vagus nerve).
• Tachycardia and hypertension may be also attributed to the carotid sinus reflex.
• All other laboratory studies show changes that are similar to condition accompanying central shock. Choking acts as a stressor on the circulator and hypophysio-adrenocortical system.
• According to their experience, no deleterious after effects remain after being "choked."

The reports showed that choking is considerably less dangerous than a "knock-out" in boxing provided necessary precautions are taken.

• Do not choke subjects with cardiac disorders or hypertension.
• Do not choke youngsters whose central nervous system and heart have not yet attained complete development.
• Do not continue to choke after the subject falls unconscious.

Since the advent of judo, first developed by Professor Jigoro Kano in 1882, no death directly attributed to choking has been reported. There are four main reasons why fatalities do not occur: 

• Choking, whether in practice or competition is supervised and observed by qualified trained instructors and officials.
• The contestant submits before unconsciousness occurs.
• After choking, the contestant regains consciousness naturally and spontaneously without difficulty in ten to twenty seconds.
• The immediate application of artificial respiration by the qualified instructor or official prevents prolonged hypoxia.
  

Sources

Koiwai, E. K. (1999). How Safe is Choking in Judo?

Ohlenkamp, Neil. (1995). Principles of Judo Choking Techniques.  [Online]. Available: http://Judoinfo.com/chokes.htm [2004, December 31 ]. Used with permission.