Knockout facts for kids

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Ingemar Johansson and Floyd Pattersson 1959
Ingemar Johansson knocks Floyd Patterson out, becoming boxing heavyweight champion of the world June 26, 1959

A knockout (abbreviated to KO or K.O.) is a fight-ending, winning criterion in several full-contact combat sports, such as boxing, kickboxing, muay thai, mixed martial arts, karate, some forms of taekwondo and other sports involving striking, as well as fighting-based video games. A full knockout is considered any legal strike or combination thereof that renders an opponent unable to continue fighting.

The term is often associated with a sudden traumatic loss of consciousness caused by a physical blow. Single powerful blows to the head (particularly the jawline and temple) can produce a cerebral concussion or a carotid sinus reflex with syncope and cause a sudden, dramatic KO. Body blows, particularly the liver punch, can cause progressive, debilitating pain that can also result in a KO.

In boxing and kickboxing, a knockout is usually awarded when one participant falls to the canvas and is unable to rise to their feet within a specified period of time, typically because of exhaustion, pain, disorientation, or unconsciousness. For example, if a boxer is knocked down and is unable to continue the fight within a ten-second count, they are counted as having been knocked out and their opponent is awarded the KO victory.

Technical knockout

A technical knockout (TKO or T.K.O.), or stoppage, is declared when the referee or official ring physician decides during a round that a fighter cannot safely continue the match for any reason, without the need for an intervening count.

In most regions, a TKO is declared when a fighter is knocked down three times in one round. Other reasons for stopping a fight include severe facial lacerations and a fighter's inability to put up a sufficient defense following a knockdown.

In MMA bouts, the referee may declare a TKO if a fighter cannot intelligently defend him/herself while being repeatedly struck.

Physical characteristics

SingletonBox-knockout
A knockout can be characterized by unconsciousness
The knockout blow in the Dempsey-Willard battle LCCN2013646088
The knockout blow

Little is known about what exactly causes one to be knocked unconscious, but many agree it is related to trauma to the brain stem. This usually happens when the head rotates sharply, often as a result of a strike. There are three general manifestations of such trauma:

  • a typical knockout, which results in a sustained (three seconds or more) loss of consciousness (comparable to general anesthesia, when the recipient emerges and has lost memory of the event),
  • a "flash" knockout, when a very transient (less than three seconds) loss of consciousness occurs (in the context of a knock-down), and the recipient often maintains awareness and memory of the combat
  • a "stunning," a "dazing" or a fighter being "KO'ed on his feet", is when basic consciousness is maintained (and the fighter never leaves his feet) despite a general loss of awareness and extreme distortions in proprioception, balance, visual fields, and auditory processing. Referees are taught specifically to watch for this state, as it cannot be improved by sheer willpower and usually means the fighter is already concussed and unable to safely defend themselves.

A basic principle of boxing and other combat sports is to defend against this vulnerability by keeping both hands raised about the face and the chin tucked in. That could still be ineffective if the opponent punches effectively to the solar plexus.

A fighter who becomes unconscious from a strike with sufficient knockout power is referred to as having been knocked out or KO'd (kay-ohd). Losing balance without losing consciousness is referred to as being knocked down ("down but not out").

Repeated blows to the head, regardless whether they cause loss of consciousness, are known to gradually cause permanent brain damage. In severe cases this may cause strokes or paralysis. This loss of consciousness is commonly known as becoming "punch drunk" or "shot". Because of this, many physicians advise against sports involving knockouts.

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