Punch Question

Heh, not fair...

Snapping a whip or towel creates (I seem to recall) a second-order velocity gradient along its length and therefore increases impact speed rather a lot.

Since ke = 1/2 (m v squared), obviously snapping a whip or wet towel increases kinetic energy and therefore the capacity to take lumps out of the target.

This is somewhat different to the situation where two objects are moving with the same energy; one is allowed to penetrate and the other is halted by an outside force.

In the flicked vs followed-through towel case, the flick causes a change in velocity at impact and therefore is an entirely different case.

I'm wondering if perhaps the intention to hit/pull rather than hit/push somehow causes a similar change in speed and therefore impact energy. If this were true then we're talking about two entirely different strikes because impact energy is different. In that case all I need is to understand how the pull/push change affects velocity and all will become clear.

What I'm still not getting is how, given that velocity is the same at initial impact, you can benefit from not delivering all that energy.

Yes, we're talking about two different strikes...ergo, snap and thrust. Different strikes for different purposes.

Si...the snap backfist moves along exactly the same trajectory as the whipped towel and doesn't have body behind it.

Also, moving the bag is wrong. A good punch will break the chain and the bag won't move one bit (except down when the chain breaks)

Nick

Nick.. dont EVER apologise for coming in on 'my' slot mate.. its what should happen....(although I did prefer TEAPOT)

One aspect not mentioned is 'grounding' its the best way to know that your 'energy' is going to damge not 'move' and opponent

Martin I can show you the best damage inducing strike in about 4-5 minutes next time we meet...

But the advice you have had on here is sound mate

Yeah, thanks everyone. I'm just trying to comprehend what seems to me to be duff physics. I suspect Nick is right and we're talking about two different strikes here, and that what I was told way back when was... dubious shall we say.

I'll look forward to those 4-5 minutes, Dave. How much will it cost to have you demonstrate on Chris????

a coffee and a bun mate

What do I get for a doughnut?

for a doughnut it aint what YOU get.. its what CHRIS gets Ha Ha

Is there a Greggs near Andy's place? I'll be making a stop on the way down...

I don't know if it's been said before but in Bruce Lee's Tao of Jeet Kune Do there is an explanation of the snap punch and its benefits.

Hi,

a very short physics explaination is mentioned here:

http://en.wikipedia.org/wiki/Impact_force:

the faster an object decelerates upon impact (pulling the punch back) , the less time there is for the receiving object to disipate the received energy and thus the more fracturing in the receiving object will occur.

Take care

That seems like flawed physics to me. By pulling the punch back you cause it to decelerate faster, it's true, but you do so by providing a decelerating force with your arm. By NOT pulling back, you cause the decelerating force to have to be provided by the target tissues.

Have you had someone hit you in different ways so you can feel the difference yet Martin?

Ade, you're an SDF man. You know the answer to that is "no but I will"

I've been hit a lot of different ways, though rarely under laboratory conditions.

My experience of piston-type punches to the chest is this:

1. Snappy, pulled back at surface contact, hurts but nothing serious.
2. Pushy, driven home but more tense/pushy than fast: hurts less
3. Fast AND driven home.... very unpleasant.

I understand the principle of delivering force in as close to zero time as possible, but my understanding of physics suggests that if you pull a strike off the target you reduce its overall energy.

Now, a slow strike delivers energy over a long time and just pushes the whole target away. A fast strike with the same force delivers it quickly and thereofre in a more localised area (no time to push the whole body away so the force is concentrated in the local area).

But... you can only deliver the whole of the energy you've developed if the target absorbs it all. If it's pulled off it loses some; if the target moves instead of absorbing, then energy is wasted.

Also energy is half mass times velocity squared so if momentum is the same for two strikes then the faster one at the moment of contact has more energy.

I'm wondering if the intention to snap a punch causes a greater emphasis on speed than the intent to ram through, in which case the effect would be better indeed.

Would say the correct intent helps improve the blow rather than Just the punch ?

That's sort of what I'm wondering. If a slightly different intent leads to a blow that's faster rather that pushier, which would indeed have different effects.

Otherwise raw physics suggests that applying a decelerative force from a source other than the resistance of the target reduces impact energy and therefore effect.

I think.

Think you pretty much summed it up there MJD, When I used to teach KB, I used try explain the difference between a punch and A PUNCH, getting them to hold the pads and they would punch, then I would go and show them a punch and then show them A PUNCH wether its a hook or straight cross even leading jab, that a difference is made by the intent. from tip tap to rock solid blows, no difference in technique, just my mind set/intent, I feel my self intent plays alot in to it. guess its that RSD moto hit them fooking hard

I took my kettlebells and a few other things down to the beach this morning to chuck them about. While I was down there, I did a little experiment with some bowling balls. I threw them using the same mechanics as a punch. I found that by whipping the hand back at the end, they went much further than just leaving the hand there. Try it...

I've noticed when teaching beginners how to punch that, if you focus on a good immediate recoil (i.e., the 2nd half of the movement being fast) the 1st half of the movement will be faster as well. I agree with what others have said on here...a hard snap back in conjunction with a range that is penetrating past the target will be the best. Over-emphasize one aspect r the other (the penetration or the snap back) and you lose some of the benefit of the other.

My original query was about the assertion that you should snap back *at the surface*, ie the instant contact began. I can't find a justification for that in practice or physics, but I *can* grok how intent alters the characteristics of a shot...

Nick Hughes said it perfectly - "I try to bring the arm back twice as fast as I threw it" - the key to good boxing shots, and getting "snap", possibly becaise it increases the accleration of the shot, which is the key to impact delivery.

Get yourself along to a Mick Coup foundation seminar, where you can see the answer to your exact question actually being demonstrated on a live person with a full explanation of the physics.

Having been on the receiving end, I can assure you the difference is palpable.

Thee is a knack to the "time on target" questinthough, as Nick says, allow enough penetration before recovering the shot, but do not alow it to become a push.

Bruce Lee's "one inch punch" is actually a "one inch push" - a transference of force into total mass, it didn't hurt the victim however.

When you are hitting the bag correctly, in my opinion as a thai boxer, it should jump and bend as if a bomb had been detonated next to it, not swing around like it is being pushed.

Yeah... I generally make the bag shudder rather than swing.

I think I've got the answer now - it's not pulling the strike off that increases the power in defiance of physics, it's the intent to do it that alters the characteristics of the strike.