Maximum power at height

FearlessFreep

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I was working on my stading bag this morning and I realized I was getting a lot more power out of my spinning side kick then I had thought (judging by how far the bag displaces in regards to other strikes). One thing I noticed is that I seem to get more power in a stright shot to the mid section then in a higher kick.

This had me wondering the reason. The way I see it, there could be a few reasons

1) I'm not flexible enough to get a high sidekick and still drive with power. Also possibly balance in that with a lower kick I have more balance so it's easier to drive more power into the target (in other words, my lack of experience makes the lower kick more powerful than a higher kick)

2) I'm driving upward into a vertical surface so the energy from the strike is a bit wasted on this kind of target and would be different against a live target

3) Bio-mechanics. The structure of the hips, legs,etc...simply makes the the alignment of everything work more powerfully when going straight out from the body then up.

If it's the first then I just need to practice more. If the second then I just need to set my expectations for knowing what the reaction of the bag means in terms of what I did. If it's the third than I just need to keep that in mind when choosing kicks versus targets versus desired results.

If it's something else or some combination or...

...anyone have thoughts?

Is this true with other kicks? Are there biomechnical realities that impinge themself upon the power of certain kicks at certain heights or...
 

MJS

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MOD Note

Thread moved to TKD per request in post #2

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barriecusvein

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As you are kicking a vertical surface, the force put 'into' the bag falls off as the product of the force of your kick and the sin of the angle between the bag and your leg, so F(bag) = F(kick)sin[FONT=lucida console,andale mono,gulim,batang,simsun,simhei]φ[/FONT] (sorry for the maths mumbo jumbo, i'm a physicist, spoiling things by using maths is what i do!).

In reality, this means the maximum power from your kick will be transmitted into the bag when you strike it with a completely horizontal kick. So pretty much your second point. Theres not much you can do to avoid this loss of power, short of growing an extra 4 feet so your new horizontal kick is where the old high one was.

As you say though, against a live target you will probably be aiming to drive the kick into the throat or neck, where the surface you are hitting is not vertical, so much more power can be transmitted.

Also, i would imagine there will be biomechanical reasons for less power because the muscles have to lengthen to allow your leg to get higher. This means they can contract less when you throw the kick so they generate less power.
 

TigerWoman

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In WTF TKD, the power comes from the snap. Also as you get more conditioned and your core, balance, flexibility and strength in your legs get stronger, your high kick gets stronger too. I wouldn't do a spin heel (hook) to a bag though as you will hyperextend your knee. Better to do that on a paddle or a target that gives. TW
 

Martial Tucker

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FearlessFreep,

First of all, I love your name. It makes me laugh and think of Yosemite Sam every time I see it.

As for your question, if I understand it correctly, I have a couple of "checks" for you. Both involve your "support leg" that you stand on as the other leg is
extending.

1. Make sure the knee of your support leg is not locked, or even totally straight when you fire the kick. If it is too straight, or locked, it will affect your balance and ability to kick higher with power. Your support knee should have a slight bend to it. Think of the support leg as more of a shock absorber than a support.

2. The heel of your support foot should be pointing right at your target.


These are fairly basic things, and I'm guessing you've got them under control, but whenever I hear the question you asked, these are the first things I always check.
 
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FearlessFreep

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Good calll on the Yosemite Sam reference. I did some stupid stunts as a kid so my dad started calling me that and it makes a good 'net nickname

#2 I have down. In fact I was spening some time in the restroom at work today trying some straight sidekicks and checking how my foot angle compared to the height I could get well (seem to affect hip angle which seemed to affect how much I could open up and therefor how high I could get....maybe I'm crazy but I definitely know that one!)

#1 I admit I really don't know, I'll have to check. I had not thought about that so I'll have to see what I'm doing

Thanks!
 

Marginal

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Any kick is always going to be more powerful when it's level with the hips. You always sacrifice power and range the higher you go with a standing kick. No amount of training's going to overcome biomechanics. (Reed Richards might pull it off.) If you want to deliver full power to a higher point, that's what jump kicks are for.
 

jdinca

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Marginal beat me to it. The same goes for arm strikes straight off the shoulder.
 

TigerWoman

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I wouldn't say no amount of training will provide power as a spin heel is pretty elemental in WTF TKD. That's defeatist. The snap does provide the power. We go from a one hand hold, to two finger hold, to a dropped board, to 360 blind folded --all spin heels. We add on the jump, yes to increase power so that the two finger hold is possible for a black belt candidate. I had to do the dropped board for 2nd dan with no jump so as your power increases the possibilities increase. My instructor's legs are actually shorter than mine, he has less flexibility too but his core and leg power is stronger. Keep practicing. TW
 

Marginal

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TigerWoman said:
I wouldn't say no amount of training will provide power as a spin heel is pretty elemental in WTF TKD.

With all due respect, that's not what I said. I said power is sacrificed (as is range) as the kick's raised. That means a kick at hip level's at optimum power. A head kick will be less powerful, but that does not mean the kick will be powerless. You can train to deliver a powerful head kick, but you will still be physcially capable of delivering a stronger kick at hip level. You're not training to offset that power loss. It's built in. You're training to increase overall power.
 
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FearlessFreep

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If I can guess, I think Marginal's point was not about the power of the given kick per-se but more about relative power between kicks. In that however powerful a given high-kick is, your same verion of that kick is going to be even more powerful at a medium level. I don't think he was implying that you couldn't make that high kick powerful, just that it wil never be as powerful as the same kick at hip level. The more powerful the high kick, the still more powerful the medium kick.

I don't know enough to say if that's true or not, which is why I'm asking these questions after all, just trying to clarify what I think he was trying to say

-------
...and I started that post before Marginal did his but I typed too slow : )
 

Martial Tucker

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Marginal said:
With all due respect, that's not what I said. I said power is sacrificed (as is range) as the kick's raised. That means a kick at hip level's at optimum power. A head kick will be less powerful, but that does not mean the kick will be powerless. You can train to deliver a powerful head kick, but you will still be physcially capable of delivering a stronger kick at hip level. You're not training to offset that power loss. It's built in. You're training to increase overall power.
I agree with this, but the good news is, as you kick higher and higher against an opponent's body it takes less and less power to move/unbalance them because you are moving your force higher and higher above their center of gravity. That's not to say I personally favor high kicks, because I don't. It's very rare that I would kick above waist level, but I know if I do go high for a "change-up", the natural loss of power is largely, if not completely offset by my opponent's center of gravity being much lower than where I am striking him.
 

TX_BB

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FearlessFreep said:
I was working on my stading bag this morning and I realized I was getting a lot more power out of my spinning side kick then I had thought (judging by how far the bag displaces in regards to other strikes). One thing I noticed is that I seem to get more power in a stright shot to the mid section then in a higher kick.

This had me wondering the reason. The way I see it, there could be a few reasons

1) I'm not flexible enough to get a high sidekick and still drive with power. Also possibly balance in that with a lower kick I have more balance so it's easier to drive more power into the target (in other words, my lack of experience makes the lower kick more powerful than a higher kick)

2) I'm driving upward into a vertical surface so the energy from the strike is a bit wasted on this kind of target and would be different against a live target

3) Bio-mechanics. The structure of the hips, legs,etc...simply makes the the alignment of everything work more powerfully when going straight out from the body then up.

If it's the first then I just need to practice more. If the second then I just need to set my expectations for knowing what the reaction of the bag means in terms of what I did. If it's the third than I just need to keep that in mind when choosing kicks versus targets versus desired results.

If it's something else or some combination or...

...anyone have thoughts?

Is this true with other kicks? Are there biomechnical realities that impinge themself upon the power of certain kicks at certain heights or...


It’s kind of none of the above; your bag is sliding more because you’re hitting it closer to the bags center of gravity.

All kicks will have individual biomechanical optimizations here are some aproximates:

Back kick is near solar plexus high.
Roundhouse kick is around chest high.
Front kick is around goin level.

These general spots will also depend on each individuals conditioning and abilities.
 
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FearlessFreep

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It’s kind of none of the above; your bag is sliding more because you’re hitting it closer to the bags center of gravity.


Had not thought of that.

Back kick is near solar plexus high.
Roundhouse kick is around chest high.
Front kick is around goin level.


One thing that occurred to me in reading that list is that, while you didn't mention any high targets, you also didn't mention any low targets, either. I know there are people (and I've heard it said myself) who say not to kick above the waist, and I guess there are tactical reasons for it, but from this I also take it that for most kicks you're going to get your maximum powerat targets that are above the waist. A roundhouse to the knee is not going to be as powerful as a roundhouse to the chest, for the same person. I mean, there could be other tactical reasons for a roundhouse to the knee, but it's interesting to think in terms of power generation about a roundhouse to the center body versus to the knee.

This all assume a relatively standing position. There seems to be an optimal body positioning in terms of hip, leg, etc...for maximum power from a biomechanical point of view. I didn't mention it earlier but I like what TigerWoman said in that, given a certain optimal 'body shape' for power in a kick at a given height, you can use jumps to change the height of your hips in throwing the kick. So you can maintain tha optimal body positioning at different targets by changing your hip height, and thus can get that maximum power to the head not by kicking up at it from standing bu kicking sideways at it straight out from the hips, from a jump
 

TigerWoman

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Marginal said:
Any kick is always going to be more powerful when it's level with the hips. You always sacrifice power and range the higher you go with a standing kick. No amount of training's going to overcome biomechanics. (Reed Richards might pull it off.) If you want to deliver full power to a higher point, that's what jump kicks are for.

I was just quoting you about the "no amount of training is going to overcome biomechanics". You could say a direct shot into the solar plexus could be stronger-3 boards worth say, I agree with that. But I have also seen 3 boards being broken with a jump spin heel to the head. Then it would be possible to break 4 boards to the chest etc. What I had issue with was the no amount of training to be able to have the same strength, biometrics do make it possible as do other factors. TW
 

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