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Effects of chokes and strangles


Studies and experiments with human subjects and animals and over a hundred years of their use in judo training and competition have shown the following effects from chokes and strangles.


According to Spitz and Fisher's Medicolegal Investigation of Death: Guidelines for the Application of Pathology to Crime Investigation (the bible of forensic pathology), five pounds of pressure per square inch is sufficient to occlude the carotid arteries and jugular veins. Thirty-two pounds are required to block the windpipe (trachea). 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 or strangling. After release from the hold, the subject regains consciousness naturally (spontaneously) without difficulty in 10-20 seconds.
  • Pressure on the larynx and trachea during chokes produced excruciating pain but there was no pain in strangles before unconsciousness.
  • The unconsciousness resulting from choking and strangling 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 a disturbance in the blood 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 much like the conditions accompanying central shock. 
  • Choking and strangling acts as a stressor on the circulator and hypophysio-adrenocortical system.
  • According to people who have been choked or strangled during training and competition, no deleterious after effects remain after being choked or strangled.

Choking and strangling safety

Reports have shown that choking and strangling is considerably less dangerous than a "knock-out" in boxing provided necessary precautions are taken. These precautions include:
  • Do not choke or strangle people with cardiac disorders or hypertension.
  • Do not choke or strangle youngsters whose central nervous system and heart have not yet attained complete development.
  • Do not continue to choke or strangle after the person falls unconscious.
Since the advent of judo, first developed by Professor Jigero Kano in 1882, no death has been reported that was directly attributed to choking or strangling. There are four main reasons why fatalities do not occur:
  • Choking and strangling, whether in practice or competition is supervised and observed by qualified trained instructors and officials.
  • The contestant usually submits before unconsciousness occurs.
  • After choking or strangling 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.

Possible deadly effects

Although it is near impossible to choke/strangle a person to death during training or competition, 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 somewhat 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.
There are two reasons this is a rare occurrence. Number one, the sensor is small and difficult to reach, so it is merely 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

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. This may also occur even if the opponent is face down,

  • Koiwai, E. K. (1999). How Safe is Choking in Judo?
  • Ohlenkamp, Neil. (1995). Principles of Judo Choking Techniques. [Online]. Available: [2004, December 31]. Used with permission.

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