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World record kick to the groin

Is a man capable of withstanding a kick that delivers over a thousand pounds of pressure directly to his groin?

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What are the limitations of the human body? How much punishment can our bodies take? Is a man capable of withstanding a kick that delivers over a thousand pounds of pressure directly to his groin?

In this clip from the television series Sport Science, we see American Gladiator and one-time mixed martial artist Justice (real name Jesse Justice Smith, Jr.) deliver his hardest kick, directly to the groin of lifelong martial artist and combat ki master Kirby Roy. Appearing unafraid to kick with the entirety of his force, Justice lands a ferocious blow to Roy’s groin that would leave most men lying on the ground, weeping and writhing in agony.

Somehow, the combat ki expert is able to absorb the blow and shake the hand of a clearly baffled Justice, who had apparently put all he has into the kick.

“That was a strong kick,” Roy concedes, while showing no ill effects from having just been kicked between the legs with such force that bystanders couldn’t help but wince.

The kick is then said to have traveled at 22 miles per hour and to have delivered to Mr. Roy’s unprotected groin an astounding 1,100 pounds of force.

It is then explained that after incurring countless strikes to the groin over the last five years, Kirby Roy’s nerves process only ten percent of the neurotransmitter that is necessary to communicate pain from the testicles to the brain.


This is by no means the sole time the group appeared in media to demonstrate their efforts. This second clip comes when JMMA legend Genki Sudo tested his ability against them. Even a straight to the throat, a body kick, and a groin kick had no major effect.


Here four large Dallas Cowboys American football players punch an adept in the neck, and a placekicker kicks him in a place.



Here pioneering kickboxer and MMA fighter Masaaki Satake tees off on deez nuts. The JukoKao representative was wearing no cup (Satake checked).


This documentary went behind the scenes of training Combat Ki.


And this one is from TruTV's Most Daring series.


Unlike most stunts in martial arts, like no touch KOs, this is real, sort of. These students really don't wear cups, and really do take a shot to the groin, body, and neck, albeit typically while moving away slightly. The groin defense technique is reportedly to tighten the butt cheeks, and tilt the pelvis. The throat defense technique is reportedly to tighten the neck; doing so retracts the throat, and brings muscle forward. But still, while the throat and solar plexus never were the deadly spots taught in 70s karate classes, as Jim Brown said during his UFC 1 commentary, "That's gotta hurt."

There is obviously no ki involved in any of it, or the group could take a shot to the nose. And there's obviously no practical use, or someone would have verifiably used it to win a fight, at least once. 

A friend of a friend used to win bar bets by saying, "I'll bet you $20 I have your name tattooed on my dick." Most people took the bet, and the reveal was indeed a tattoo, ummm, there, that read "your name." JukoKai feels the same - it's colorful, but seems like a lot of trouble for little reward.

The group got a lot of publicity in the 1990s, but it has died out over the past decade. Anyone interested in further information should check out

Share your thoughts about JukoKai, Combat Ki, and voluntarily getting kicked in the jimmy, on The StreetGround forum at