Re: Punching

RichD wrote: 
Mark Fergerson wrote:

You want to perform the standard right hand punch (with left foot
forward), as powerfully as possible.


  First consider what you mean by "power". You posted to
sci.physics, so let's get dimensionally analytical.

Good idea. 

  P=M/LT^3, which can be broken down into mass accelerating over a
time period.

uhhhhhhh.......

Whoops. Obviously, should be P=ML^2/T^3, and rate of energy transfer. Sorry, lack of sleep.

  A punch is basically applying your fist moving at some velocity
to some part of an opponent's anatomy which will absorb the kinetic
energy by deforming, thus decelerating your fist. Generally you want
to maximize contact velocity

Yes

and minimize dwell time, no?

Except you can't control that. 

  That's why I said "want to".

It's determined by the vicsoelasticities of the objects in collision.

Yep, but a fist is relatively rigid compared to the tissues underlying the famous seven body targets (otherwise we wouldn't ever punch with our fists) and good muscular control minimizes the contribution of the target's composition; Bruce Lee's "one inch punch" frinst.

  You pose two scenarios with one major difference; the relative
velocity between you and your opponent. In the second, you have to
deal with the attacker's momentum; after a successful strike you
don't want him knocking you down.

'successful' implies I do not get knocked down. 

  ;>)

If I try to hit an onrushing elephant, chalk it up to bad judgement. 

<insert chorus from Kenny Rogers'"The Gambler" here>

So you have some options; you can
plan on ducking aside and letting him go past you, you can redirect
him so he goes past you, or you can stop him WRT you. ISTM that what
you do with your feet depends on your choice.


  To stop him cold, you want to put your fist in front of his
center of mass and brace yourself firmly enough to absorb
all his momentum which seems to imply not lifting your rear
foot at all.

BTW, you snipped the bit about the One Point; somehow I said "above" instead of the correct "below". Duh moment, I guess.

That was the point of my question   It's not at all so obvious as you seem to think; i.e. that not lifting
is correct

Well, I did say "seems", and you're the one who used the "impaled" imagery, which a well-placed 2x4 could do. If you don't plant your foot flat, you're relying on your ligaments and tendons to absorb some of the momentum. Do it wrong and the ligaments and tendon tear, and your heel comes down anyway. Might as well plant it from the get-go and trust your bones.

Then you have to deal with a body folded over your fist. ;>)

Hope

No, plan ahead. I don't consider having a body folded over my fist a favorable outcome; I prefer maneuverability. An onrushing attacker is IMNSHO best handled by sidestepping, but then as I said, I prefer Aikido.

  Mark L. Fergerson

.

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