Topic
Herbert Cannon posted on rec.martial-arts a question about the effectiveness of targeting the kidneys in boxing:
I have heard boxers talk about this. However, the kidneys seem pretty well protected. So how much pounding does it take in this area to inflict severe punishment?
Detail
Badger South replied with a comment that most people target the wrong area for the kidneys and notes that they are a useful area for knife strikes:
In addition they're higher and located more centrally than most people think. The area that a boxer hits is usually going to affect the floating ribs more.
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The kidney is a vulnerable area particularly to knife wounds and a stab to this area is reported to immediately send the victim into shock. Blunt trauma isn't likely to have a big effect unless it's cumulative.
Badger South ventures some opinions in a later message as to whether it might be a good target area for hitting with the heels in grappling:
That's an after-effect. Nobody's targetting the kidney in order to cause an effect after the fight are they? I'm just suggesting that the shot to the lower back is really a floating rib, liver attack and not an immediate effect of something related to kidney percussion. Guess it doesn't matter - that they call it the kidney punch might just be a misnomer.
Still if stabbing the kidneys has such a strong effect, I suppose hitting them might induce weakness. This is the area that some fighters target with a heel when in guard and where there heel hits is probably much closer to being over the kidneys than the small of the back. Not trying to force a conclusion, just discussing, you know.