Delayed Sword Physics Discussion

[profesormental]

Hi all!

I recievend the Physics of MA DVD's and have read the notes and have found them a great resource for verification methods of Martial arts training.

Also, I've started giving the physics labs here so I also have access to cool measuring equipment.

So I want to start on the discussion of the techniques using the terminology and concepts that we have at hand!

Onward to Delayed Sword.

I agree with the conclusions on forward body momentum, (a.k.a changing depth). That is why many times I also push step instead of just settling down.

I also agree that downward linear momentum does not contribute to forward linear momentum, and this is obvious since the Px and Pz vectors are independent,

i.e. up and down momentum does not affect forward and back momentum, thus they do not contribute kinetic energy to each.

I also note that not mentioning this might lead to a false conclusion that downward momentum (Pz) contributes nothing to the technique.

First remember that the measuring device only takes into account Px (forward momentum) and some side momentum (Py).

also remember that the human target would be hit in 45 degrees at least... that means that the contributing momenta would be Px, Py and Pz.

So a complete analysis would include Pz on a modified target to take into account the Pz component... and the Py (side to side component of linear momentum) component, which is brought about by the rotation of torso/hips/stance and adding a sideward component to the strike.

When I practice delayed sword I try to maximize the movement in all 3 components, and I drill this onto my students... change depth, heght and width.

The sum tends to be catastrophic for any sort of structure the opponent has and the kinetic energy transfer feels horrific.

(and we're not taking into account pressure, which has to do with proper weapon formation!!!)

so in conclusion, the Px and Py components were accurately measured, the independence of Px, Py and Pz was established (they dont contribute to each other), so the Pz component does not add to the forward momentum;

yet the contributions that Pz can make to the strike was not assessed and the presentation might suggest that it contributes very little, which I consider false on the account that a human target permitts downward force to be exerted, which can be transferred maximally by proper elbow placement (anchoring) and downward movement of the body mass.

To verify this experimentally would take a bit of modification of the equipment which could include tilting Herman 45 degree and noting that you would get the resultant (i.e. Px + Pz for example) depending on the direction of tilt, or any other simple modification of the equiment.

Juan M. Mercado

[administrator]

Its great that you now have access to measurement devices! You will find that these devices, used correctly, we greatly enhance your undrstanding of kenpo and will maximize your training efforts.

To respond to some of your comments:

I also note that not mentioning this might lead to a false conclusion that downward momentum (Pz) contributes nothing to the technique. In the dicussion of Delayed Sword, the purpose of the breakdown of the zones of protection was to indicate where the power was coming from. There is a downward component associated with the handsword strike. However, it was shown that the source of the power, often referred to as Power Source among many kenpoists, is not Marriage of Gravity, but muscular strength and downward body momentum.

To verify this experimentally would take a bit of modification of the equipment which could include tilting Herman 45 degree and noting that you would get the resultant (i.e. Px + Pz for example) depending on the direction of tilt, or any other simple modification of the equiment



We used the Herman device in many angles and found the results to be very consistent. For purposes of the video, and teaching others how to set up simliar tests, we used the standing heavy bag. To measure impulse we also verified the results with other equipment. The Herman device is fairly accurate. What you should use the results for is where to emphasis your training efforts. In Delayed Sword we showed that emphasizing the stomping that so many practitioners display, is a wasted effort.

We understand that term Marriage of Gravity is a sacred cow in Kenpo, but as we had shown, it was only an analogy that Ed Parker had used to get people to "get their weight" into their strikes. Its often referred to as 'sinking' and 'grounding' in other arts.

I do know of some kenpoists who have experienced the 'gravity of marriage', but mine is a stable one;)

Keep training first, and analzye to improve your training methods,

Kevin Lamkin
Site Administrator

[profesormental]

To respond to some of your comments:

In the dicussion of Delayed Sword, the purpose of the breakdown of the zones of protection was to indicate where the power was coming from. There is a downward component associated with the handsword strike. However, it was shown that the source of the power, often referred to as Power Source among many kenpoists, is not Marriage of Gravity, but muscular strength and downward body momentum.


I agree with that conclusion. My comment was that no other mention was done to the downward body momentum as a source of power for a strike.

I also agree that the stomping is a wasted effort and if it falls before the strike it actually can cause UPWARD body momentum, which takes away power (in terms of energy transfer) and impulse (in terms of force transfer) from the strike.

I was taught the term marriage of gravity much later than the term "use your body weight" and "sink", so I have no attachment to the term.

I would rather use the proper physics term, since then repeatable mathematical models can be use to argue instead of having to do a linear transformation from other vocabulary to physics. And many times the transfoprmations are not linear... that's where you find the wasted efforts and myths.



I do know of some kenpoists who have experienced the 'gravity of marriage', but mine is a stable one;)

Good! Many have had to go to their zones of sanctuary via their angles of cancellation to avoid the path of aggression of the family groupings caused by the gravity of marriage! LOL

Keep training first, and analzye to improve your training methods,

Always.


Kevin Lamkin
Site Administrator

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Sincerely,

Juan M. Mercado

[Lance C]

Its great that you now have access to measurement devices! You will find that these devices, used correctly, we greatly enhance your undrstanding of kenpo and will maximize your training efforts.

To respond to some of your comments:

In the dicussion of Delayed Sword, the purpose of the breakdown of the zones of protection was to indicate where the power was coming from. There is a downward component associated with the handsword strike. However, it was shown that the source of the power, often referred to as Power Source among many kenpoists, is not Marriage of Gravity, but muscular strength and downward body momentum.



We used the Herman device in many angles and found the results to be very consistent. For purposes of the video, and teaching others how to set up simliar tests, we used the standing heavy bag. To measure impulse we also verified the results with other equipment. The Herman device is fairly accurate. What you should use the results for is where to emphasis your training efforts. In Delayed Sword we showed that emphasizing the stomping that so many practitioners display, is a wasted effort.

We understand that term Marriage of Gravity is a sacred cow in Kenpo, but as we had shown, it was only an analogy that Ed Parker had used to get people to "get their weight" into their strikes. Its often referred to as 'sinking' and 'grounding' in other arts.

I do know of some kenpoists who have experienced the 'gravity of marriage', but mine is a stable one;)

Keep training first, and analzye to improve your training methods,

Kevin Lamkin
Site Administrator





I have a question about Herman (I put one on order since re-watching the video.) It is an accelerometer (I work in the automotive electronics industry) How many axis does it do? Sounding by your results of tilting the impact load it perhaps measures more than one axis (creating net results?)


Off topic slightly was about "impulse" since college physics for electronics did not cover this well (or at all?) is the correct usage meaning sequential acceleration from multiple sources ie your leg pushes, your torso twists, your arm extends, when each part does its maximum job (correctly sequenced) is that what is meant by impulse?

I was thinking of the theory of the ion engine that each ion pushes off the last one causing slow, energy efficient acceleration. Would the push into push into push be impulse?

Just learning.

-Lance C

[administrator]

I found that tilting the accelerometer does not alter the results much.
For the purposes of training, the Herman device works great and is relatively inexpensive. What is being measured in the net forces on the target, therefore, you will obtain a better knowledge of what the opponent will experience when receiving such a strike.

The impulse that we measure is the change of momentum of the target. All methods of generating your body momentum prior to the strike is a matter of the component's of form; such as, balance, alignment, back-up mass, body fusion, etc. The terms just listed are not power sources - as many instructors are teaching -they are components of form, which will maximize the only "power source" that you actually have control of - Body Momentum.

So, when you are training, you must train in two areas:
1. How can you maximize your form?
2. How much energy are you actually transmitting with your strikes?

As previously stated, maximizing your form will enhance your potential power, and should be observed from your own 1st perspective, and the 3rd perspective of your instructor, training partner, video camera, etc.
When enhancing your actual transmitted power, you must consider the 2nd perspective of the oppenent, or a measurement device like the Herman.

There are other methods to more accurately measure Impulse without the Herman. However, the Herman device is the most affordable.

Kevin Lamkin
Site Administrator

[Lance C]

I found that tilting the accelerometer does not alter the results much.
For the purposes of training, the Herman device works great and is relatively inexpensive. What is being measured in the net forces on the target, therefore, you will obtain a better knowledge of what the opponent will experience when receiving such a strike.

The impulse that we measure is the change of momentum of the target. All methods of generating your body momentum prior to the strike is a matter of the component's of form; such as, balance, alignment, back-up mass, body fusion, etc. The terms just listed are not power sources - as many instructors are teaching -they are components of form, which will maximize the only "power source" that you actually have control of - Body Momentum.

So, when you are training, you must train in two areas:
1. How can you maximize your form?
2. How much energy are you actually transmitting with your strikes?

As previously stated, maximizing your form will enhance your potential power, and should be observed from your own 1st perspective, and the 3rd perspective of your instructor, training partner, video camera, etc.
When enhancing your actual transmitted power, you must consider the 2nd perspective of the oppenent, or a measurement device like the Herman.

There are other methods to more accurately measure Impulse without the Herman. However, the Herman device is the most affordable.

Kevin Lamkin
Site Administrator

Herman is on "his" way. Reading the information Mr Lamkin is changing some ideas on what we do, it is like going back a step so you can find a different path headed in the same direction. I suspect that the equipment will help out with the study part. Downloading the notes will help too.

American Kenpo is both a hard and soft art, since it uses many components (all?) Is there going to be training that incorporates basics that do not require power, but maybe timing and precision for example?

<<The Kung Fu hallway with mechanical devices to test the monks ability before getting the tiger / dragon branding on the forearms?>> Perhaps a bit outside, but what about a moving "hitmaster" that measures accuracy and reaction, or a hitmaster that fits on a chest guard etc..

Just throwing out some ideas.
-Lance

[administrator]

Is there going to be training that incorporates basics that do not require power, but maybe timing and precision for example?

All basics should incorporate some degree of power. Even a parry would collapse upon the moment of contact if it did not have the appropriate power to deflect.

All basics should be honed with precision and timing to be effective.

In our Master of the Ring Manual (http://www.elite-fighters.com/seminars/series3.htm) we give many timing drills that should do what you may be referring to.

what about a moving "hitmaster" that measures accuracy and reaction, or a hitmaster that fits on a chest guard etc.

This sounds like a good idea, but Hitmaster warns not to strap a target on. The training devices are great to give you feedback in developing power, reaction timing, speed, etc.. However, when you have a partner to train with, the Master of the Ring Manual gives you the best drills. Using a combination of both will allow you to hone your skills to a high level.

Kevin Lamkin
Site Administrator

[profesormental]

Hi!

On the topic of rooting and using your weight, for my students I emphasize it on delayed sword on the occasions of stepping back and delivering the strike...

Why is this?

FOr better energy transfer and more control of the body structure.

THe best example I can think of right now is the following:

Why do fast cars have spoilers on them?

The spoilers are used to vector the force of the wind DOWNWARD as to make the car in effect, heavier.

This makes the wheels be able to experience a force of friction that is of higher magnitude and helps them "stick" to the road...

(frictional force = mu x n where mu is a frictional constant and n is the normal force that has equal magnitude and oppositedirection than weight, i.e. upward force of the street on your wheel.)

so that more force can be transferred to the street and propel the car forward.

So when my students don't root, they cannnot deflect the strikes withoug them bouncing back or loosing their balance, which minimizes energy transfer.

When they root, strikes bounce off their blocks (intercept strikes) and they maintain balance and posture. In other words, their form.

That is that the momentum is transferred (thus the kinetic energy) as though you in actuallity weight more! So in terms of position, you remain virtually stationary and more momentum is transferred to the opponent because of conservation of momentum.

This needs more explanation but the idea is there. If you want more please ask!

I gotta go now.

Sincerely,

Juan M. Mercado

[Xperience]

Hi p-m ~
On the offensive (footwork) side of rooting (pz): I'm no physicist, but it seems to me that the increase of power by dropping the center of gravity while delivering an offensive downward strike through a target, is in the form of a compression-effect; that is the resistence caused by the target being supported by the ground, much like sandwiching the head during a forearm strike for added power. X (RWL)

[profesormental]

Hi!

You don't have to be a physicist... its just that physicista are more practiced in terms of argueing in mathematical terms using well formed formulas (the language structure of logic).

That has to do with innelastic collisions, in which the energy transferred is dissipated in deformation of the target. This way the momentum is not conserved, but the energy is transferred and used in the destruction of structures in the body by the weapon.

If the person is pushed without this deformation, there will not be that much pain from the strike... but the person will be moved further. Think front push kick vs. front snap kick. This has to do with impulse of target.

The term you're using have to do with pressure, which is another consideration in the physics of martial arts.

And if you argue that you're sanwiching the person between your hand and the floor, I would say that if you have good base (rooting) and good structure behind the arm, you have that ssandwich effect...

the floor (hard surface) and arm (hard surface with support) with target in between.

That is good input. Thanks!

Sincerely,

Juan M. Mercado

[Xperience]

Hi p-m ~
I have another analogy for you. If one does a 1" punch with emphasis on 'focus' , one gets maximum 'impulse' , and the recipient is dropped. If one wishes for 'dramatic demo effect' , one emphsizes driving through the target with the strike, creating less 'impulse' & more push. If done properly, there is a slight upward vector to the strike, lifting the recipient's center of gravity, adding to the effectiveness of the push; and the person is propelled through the air. I wasn't sure if you were familiar with the 1" punch, so I thought I'd just mention it. X

[profesormental]

Hi!

I do know and use inch power a lot... I've sent 200 pounders head over heels regularly, specially if they don't expect it and I vector upwards on their sternum.

Vectoring downwards and through the solar plexus, instead of the sternum, can cause real havoc on he internal organs.

The thing about inch power is that it has a lot of impulse plus the structure to transfer the energy completly to the target... which we enphasise on Chi sao training... which is also executed on the Kenpo techniques by virtue of such training.

Hubud and other filipino/flow drills are good for continuation of movement and fluidity, yet I've found that Chi Sao really emphasises the structure to deliver the strikes better, at the same time creating flowing and sensitive attributes.

So as was discussed before, strucrue and form to transfer energy should be also considered when doing the techniques.

This is a very good topic!

Sincerely,

Juan M. Mercado

[Xperience]

Hi LanceC & professormental ~
Well there you go LC & p-m; maybe you guys could try the 1"punch on your Herman (or whatever) measuring devices. I should think that it might be an interesting little experiment. I would be interested to see what kind of results you got. What do you think; yes, no, maybe? Anyway, you guys have a good day (you too Admin). X

[profesormental]

Hi LanceC & professormental ~
Well there you go LC & p-m; maybe you guys could try the 1"punch on your Herman (or whatever) measuring devices. I should think that it might be an interesting little experiment. I would be interested to see what kind of results you got. What do you think; yes, no, maybe? Anyway, you guys have a good day (you too Admin). X


Hi!

I would have to design an experiment and measuring devices that have to take into accoun also the pressure of the contact points, which really cause a lot of pain and damage... and don't have to hit with that much power.

Inch power punches on the sternum and hitting with the knucles only really hust and drive people back, plus the incredible power generated, plus the mental focus factor (which is quite significant!!!) amounts to a lot of varialbes.

I first use low accuracy approximations with my gym equipment (heavy bags, pads and kinesthetic comparisons) to get a feel for what has to be done. I'm getting inventory of the equipments I have available from the laboratories to know if I have to buy anything.

I'll keep you posted.

Sincerely,

Juan M. Mercado

[administrator]

maybe you guys could try the 1"punch on your Herman (or whatever) measuring devices. I should think that it might be an interesting little experiment. As part of a Physics Notes that is about to be posted next week, we did experiment with the '1-inch punch' in comparison to other types of thrust punches.

There are many factors that we report out involving different punching styles, stances, weight shifts, angles, etc. Those will be posted in the notes.

As for the 1-inch punch, it was should to deliver about 60% of a full rear hand thrust punch. The effects of the punch, especially with the Bruce Lee demonstration, are due to many factors.

From the 1-3 inch range, there is no telegraphing, therefore the element of surprise will take the demonstration partner off guard. The demonstration partner is usually in an open position, not braced as in a fighting position. The higher the target on the sternum, the easier it is to topple the partner. This is because it gives a greater angular acceration to the rear. Think of a socket wrench, the longer the handle, the easier it is to do work. An upward vector does not appreciably add to the toppling effect. For participants of equal height an upward vector is natural due to the mechanics of the strike. To verify, have someone to step on a platform and hold the target lower on his abdomen, you will not get the same effect. In contrast, you can stand on a target, and strike downward on your partner with the target high on his sternum and have a greater effect. The shift of wieght from the rear leg to the front is essential to gain greater power.This information does not belittle the 1-inch punch. The short strike is crucial in developing focus and must be part of any thrusting punch, regardless of the range. We will discuss more of that in a future Physics Notes release.

Kevin Lamkin
Site Administrator

[Xperience]

[QUOTE=profesormental]Hi!

I would have to design an experiment and measuring devices that have to take into accoun also the pressure of the contact points, which really cause a lot of pain and damage... and don't have to hit with that much power.

Inch power punches on the sternum and hitting with the knucles only really hust and drive people back, plus the incredible power generated, plus the mental focus factor (which is quite significant!!!) amounts to a lot of varialbes.

I first use low accuracy approximations with my gym equipment (heavy bags, pads and kinesthetic comparisons) to get a feel for what has to be done. I'm getting inventory of the equipments I have available from the laboratories to know if I have to buy anything.

I'll keep you posted.

Sincerely,




Hi p-m & Admin ~
Thanks for your input Admin; as you said, the results depend on the method of executing the punch. I teach the 1"punch to my beginning students in their 4th class, as part of an actual striking-combination (self-defense technique), and merely refer to it as a 'focus punch'. Ofcourse it takes them a while to perfect it, but it's a handy technique to know; and this way it gets programed into their nerve-paths early-on. They're not aware that it is generally taught as an advanced technique, because it's so simple; and it's amazing what they 'can' do, when they don't know what they can't do. Now profesormental, my execution of the 1"punch is slightly different than your (& Bruce Lee's) Wing Chun method. First, I'll explain the version I do to demo 'focus': I'll have the person I'm demonstrating on hold a 3" thick phone book (yellow pages) tightly against their right (non-heart side) pectorial muscle as a target, while standing in a 'right-lead'. I target the pec, because I don't want to hit the sternum and chance doing severe damage. I then stand in a relaxed 'right-lead', open my lead-hand (like shaking hands w/someone) 'continually' touching phone book with my finger tips. From there I integrate dropping my center-of-gravity (no step), with a relaxed horizontal piston-like punch (w/center knuckle) 1"-3" 'into' the target, while closing my hand. The bigger the person, the deeper the focus. As a result, the person will usually exhibit a concussion-effect as they take a 1/2-step back, their knees will buckle, and they'll drop heavily into the chair I had previously placed behind them. It seems to me, that this would be suitable to test 'impulse' readily enough. The version I do to demo 'projection' is identical, except I take a 1/2-step forward w/my lead-foot while dropping my center-of-gravity; and focus the punch 1"-3" 'past' the target, depending on the person's size. The punch has a slight natural lift, due to further arm-extension (& the shoulder being higher than the elbow); which seems to slightly lift their center-of-gravity & help break inertia. The general result, is that the person will exhibit a concussion-effect as they leave the ground slightly, and then land in a spotter's (who is standing about 6ft behind them) arms. This version has more of a 'dramatic' effect when demonstrated, and probably wouldn't be suitable for testing. As you said, too many variables. Anyway, that's my take on it. Hope your 'testing' works out; I'm curious about your results, as well as Admin's. :) X

[Lance C]

Hi!

You don't have to be a physicist... its just that physicista are more practiced in terms of argueing in mathematical terms using well formed formulas (the language structure of logic).

That has to do with innelastic collisions, in which the energy transferred is dissipated in deformation of the target. This way the momentum is not conserved, but the energy is transferred and used in the destruction of structures in the body by the weapon.

If the person is pushed without this deformation, there will not be that much pain from the strike... but the person will be moved further. Think front push kick vs. front snap kick. This has to do with impulse of target.

The term you're using have to do with pressure, which is another consideration in the physics of martial arts.

And if you argue that you're sanwiching the person between your hand and the floor, I would say that if you have good base (rooting) and good structure behind the arm, you have that ssandwich effect...

the floor (hard surface) and arm (hard surface with support) with target in between.

That is good input. Thanks!

Sincerely,

Juan M. Mercado




Our club's Herman came in a couple of days ago and we were very pleased to put it to use. Apparently it is much tinier than the one pictured in the video. The only complaint is that we put it on a Century Large kickshield and the results vary with how hard you brace it against your body, which can alter the results to a suprising degree. However results are consistent if the person holding it is consistent.

It really changed how you train, as a person monitoring the readout can read off sequential hit scores, and experimentation in form can take place. It is suprising how hard some children can hit, and its suprising how light some "old timers" hit.

I would round house kick the pad, knock the person holding it down and score lighter than some of the 14 year old girls who smack the shield well. Guessing, it comes down to that my kick delivers more power over more time, however lower amplitude. It would cause less damage on impact, however it could (and often) knocks someone down. The teenagers who kicked well have LOTS of speed, they deliver more "instantaneous power" and will do much more damage on impact, but there is no "lingering" push in their kicks.

I would guess the difference is in the training on "delivering power" since I have been using herman and getting feedback, I have been altering the form of my kicks and my instantaneous power is coming up.

Thanks Mr. Lamkin, I think your idea will make better martial artists of us all, after seeing the improvement just 1 class, as the competitive (self and with others) drives students into following form and executing better striking techniques. It also helps drive home the influence of Kenpo Theory.

-Lance

[administrator]

The only complaint is that we put it on a Century Large kickshield and the results vary with how hard you brace it against your body, which can alter the results to a suprising degree. However results are consistent if the person holding it is consistent.
This is one of the reasons that I place it on a Heavy bag. The bag will always remain consistent, therefore, ther results will be comparable each time that you strike it.

The Herman can also give different results depending on the mass of the target. I use a 250 lb Heavy Bag for adults to strike on, and a 80 lb for the children. If I strike the 80lb heavy bag witha strike and get a 20 'g' force results, it may only equate to 12 'g's on the 250 lb bag. That's OK for training. Children need to know what comparable results that they need for children their size.

In general, 7 'g's are needed to have enough force to break bones, 10 'g's are needed for good knock-out power. When you get a kid striking with about 12 'g's on an 80 lb bag, then you need to move him up to a 120 lb bag.

The teenagers who kicked well have LOTS of speed, they deliver more "instantaneous power" and will do much more damage on impact, but there is no "lingering" push in their kicks.
To maximize damaging power, you need to highest possible velocity with good follow-through. Following through with a high velocity will cause the target to have a greater change in momentum, thus a higher value of Impulse.

Kevin Lamkin
Site Administrator

[Lance C]

All basics should incorporate some degree of power. Even a parry would collapse upon the moment of contact if it did not have the appropriate power to deflect.

All basics should be honed with precision and timing to be effective.

In our Master of the Ring Manual (http://www.elite-fighters.com/seminars/series3.htm) we give many timing drills that should do what you may be referring to.



This sounds like a good idea, but Hitmaster warns not to strap a target on. The training devices are great to give you feedback in developing power, reaction timing, speed, etc.. However, when you have a partner to train with, the Master of the Ring Manual gives you the best drills. Using a combination of both will allow you to hone your skills to a high level.

Kevin Lamkin
Site Administrator

We had some fascinating preliminary results with Herman, we found that size was not a major factor in scoring. We have a 9 year old girl in class that weights about 50 pounds and is totally flexible (she can go past the splits, like a pulled back bow) it looks like her degree of flexibility and control allows her to hit without resistance and hits as hard with a roundhouse kick as most of the adult men. Her speed is incredible, we are trying out the action / reaction mode that herman has built in (new version)

What we found was that at our club, most of the power training people have driving round house kicks that score low, as they are putting out more total power, but over a greater amount of time (target acceleration reaches 0 fast) however they have the strength to push someone to the ground with the kick, and the ground does the damage. Where as having a high acceleration and impact causes a higher reading, it does not measure "pushing kicks" due to their slower speed. Pushing kicks do less damage on impact, relying on target displacement (kicking someone over a cliff for example) for their effectiveness.

Herman appeared to be a great tool to work on:
Speed Shot (similar to the hitmaster) however it does not accurately measure how many hits in a timed session. Our fast guy hit about 60 times, the unit counted 24. The mode is supposed to work, however testing disproved this function.

Timed Total Power output. That is 10 or 30 seconds and see how much damage you can do.

and 15 technique hit mode. Used with spotters and trainers allows form to be instructed with feedback on power.

The speed shot worked well with self defense techniques, and herman can be ganged with up to 5 sensors and a Personal computer now, so multiple hits to multiple targets can be measured in both speed and timing. We are looking at getting this feature and making special anthropromorphic fixtures that can be tailored to self defense technique targets. An idea of power distribution in your self defense techniques can be found in this manner.

We found that the feedback from herman had instant results in the athlete's power output, and especially their form! You have a tendancy to keep your "head over ass" balance better, and when using gravity kicks etc.. you recover better, otherwise your next strike will be off target and or weaker. The timer functions make your form better since you are under some stress to get a higher score. This makes good use of competitiveness (with yourself and others)


-Lance

[Lance C]

This is one of the reasons that I place it on a Heavy bag. The bag will always remain consistent, therefore, ther results will be comparable each time that you strike it.

The Herman can also give different results depending on the mass of the target. I use a 250 lb Heavy Bag for adults to strike on, and a 80 lb for the children. If I strike the 80lb heavy bag witha strike and get a 20 'g' force results, it may only equate to 12 'g's on the 250 lb bag. That's OK for training. Children need to know what comparable results that they need for children their size.

In general, 7 'g's are needed to have enough force to break bones, 10 'g's are needed for good knock-out power. When you get a kid striking with about 12 'g's on an 80 lb bag, then you need to move him up to a 120 lb bag.


To maximize damaging power, you need to highest possible velocity with good follow-through. Following through with a high velocity will cause the target to have a greater change in momentum, thus a higher value of Impulse.

Kevin Lamkin
Site Administrator

Those are different scores than what we are getting with the kick shield.

some prelim observations:

We have a class average of 20 g's on the kick shield in the adult class (score's are g force x2, it scored average of 40) and that is generally with martial artists of 2+ years of experience, mostly 20-30 year old males. Experience and enthusiasm were definate contributors in performance. That was using the same guy, same holding technique and seemed fairly (but not perfectly) consistant.

The instructor proved well at 38.5 g's and knocked the two guys bracing it down. However he is 145 kg and 2m tall, with 20 years backing it ;)

We tried herman on a 60lb heavy bag and had horrible results. It did not read well, and often double triggered, the chain causing the bag to jump would cause multiple readings. We even shock corded it with even worse results.

We will try a wavemaster next or a makiwari board next (wall mounted bean bags and makiwari are popular with the students for punching techniques)

The heaviest puncher (step through right punch) was about 25 g's with a class average of 15 g's on the same shield.

Back Fists were way higher, some individuals maxed out at 30 g's with an average around 24 g's.

-Lance C

[administrator]

I'm glad to hear of positive results with this training device. Its good to have impartial feedback that you can rely upon. I have also found that my students get a better workout with feedback devices, because they are competitive with themselves, and therefore, try to improve their score.

Kevin Lamkin
Site Administrator

[Lance C]

I'm glad to hear of positive results with this training device. Its good to have impartial feedback that you can rely upon. I have also found that my students get a better workout with feedback devices, because they are competitive with themselves, and therefore, try to improve their score.

Kevin Lamkin
Site Administrator

Herman's webpage has lots of neat free downloads to modify the programming with. Very versatile device!

We found that the opinion of the kick shield holder varied from Herman. Certain hits found in Kenpo that manipulate the pivot points of the body can be fairly light but feel like a hard hit. Hitting the side of the pad causes the shield holder to "teeter" to the side, this movement makes the shield holder feel a harder hit was executed due to the suprise movement, they would judge the hit harder. However a full impact against a well rooted target would feel less, even though the pad was fully compressed and the shield holder bruised.

We found that a better group understanding of what is going on with form came about much faster (sometimes minutes) was achieved due to the feedback.

As a coaching device and entertainment supplement Herman works well.

Lance C