A ridiculous but simple way to test the strength and power of your strike!
From time to time I receive letters with the following content: “Hello Denis! I noticed that after studying and working through the materials of your lessons, the power of my blows has increased significantly! But how can I determine whether my blow can really be considered strong? How can I check if I have a hit without resorting to special devices and training equipment? Thanks in advance!”
I decided to present the answer to this question in the form of this article, and the method of testing the strength and power of a blow is truly unusual!
Before moving directly to the coverage of this method, I would like to tell you how it “came into being.” And he appeared many years ago, during the first years of my studies at the institute. In those days, sometimes there came moments when, for no apparent reason, all desire to study disappeared (students will understand me) and a small group of us successfully skipped some classes :)
Don't think that I'm some kind of slob, who did nothing but skip classes at the institute! No - I studied quite well, but sometimes it was simply a sin not to skip some class, especially when the weather is good outside and you have just received your modest scholarship, which your fellow students are almost forcefully trying to wash :)
So...
On one of these days, my friends and I gathered on a small lawn near the lake and for some reason the conversation turned to my person as a boxer. The fact is that my appearance could not be called a boxer’s with its characteristic boxing haircut and broken nose. Therefore, after the Nth amount of beer, my friends yelled in one voice: “Come on, prove to us that you are a boxer!”
I asked - how?
To which they answered: “Well, hit something!”
I agreed and everyone rushed to look for this “something” that could be broken with a blow. They didn’t find anything worthwhile and everyone seemed to have calmed down...
But then one of my friends said that he had a durable plastic bag (students, as a rule, are not very rich, so very often they carried their modest student luggage in various bags).
The package was small, but really very durable! It was practically impossible to stretch it. If my memory serves me correctly, it had the mark “ breaking load— 25 kg!”
I said that I would have no problem making a hole in this “super bag” with my blow! But then one of my fellow students, the largest of us (weighing about 90 kg), exclaimed: “Yes, I’ll tear this bag to shreds myself, even though I’m not a boxer!”
Well... Let it be so!
I gave in and gave my friend the opportunity to prove himself, took the bag and stretched it out at arm's length, preparing a kind of “strike surface.”
A friend announced to everyone: “Study, students!”
After which he hit it quite sweepingly and... DID NOT PUNCH THE PACKAGE!!! Several more blows followed, but the package turned out to be stronger! After that, my other two “compatriots” also expressed a desire to show the “strength and power” of their blows!
And none of them broke through this package! After that, they all unanimously told me that it was simply impossible to break through this package!
I had to dispel their doubts - the package was punched with the first blow!
The hubbub started again: “Yes, we’ve already stretched it out for you and you’re just lucky!”
I said that next time we’ll take a completely new package and I’ll hit it first so that no one has such doubts. And indeed, in the future I did a similar “trick” with completely new packages!
And the secret was precisely the correct striking technique! Friends had no idea that when delivering a blow you need to transfer your body weight from one foot to another, that you need to put your body into the blow, etc. etc...
What’s most interesting is that all the “test subjects” were 20-30 kilograms heavier than me! But without correct technique their blows were very weak...
This ridiculous, but effective way of testing the force of a blow was then, as they say, born!
If you want to test the strength and power of your strikes, then you will need a bag made of very durable material. There are small (about 35x25 cm) but very durable plastic bags - it is better to use them.
Or you can find an equally durable “alternative”. Now many supermarkets offer customers large packages made of very durable material - you can use them with confidence!
After the required package has been found, you need to find a person who agrees to help you. He will need to take the bag, fold it in half (if you don’t fold it, it won’t be so difficult to pierce the bag) and stretch it with outstretched arms so that you get a striking area with a distance of about 30-40 centimeters between the hands.
Have the person pull the bag tightly enough to create a solid surface into which you can strike directly with your back hand.
But be careful - don’t miss and don’t fall into the hands of the one holding the package for you!
If you pierce the package the first time and without problems, you can consider that you have a well-placed direct blow! You can also apply two.
But do not forget that the supermarket bag should be strong (ask for a “large” bag), it should be folded in half and the distance between the hands should be approximately 30-40 cm. For a better understanding, imagine that your assistant is pulling a small towel with his hands and holds it on outstretched arms in front of you, and you deliver your direct blow (with your back hand) to the center of such a striking surface.
I haven't tested the strength of side and bottom punches this way, but I think the effect would be the same as with a straight punch.
Check impact force - YouTube
How to measure impact force - YouTube
The sixth year of the third millennium is ending, new generations of athletes are passing into history, but the problem of measuring the force of an impact remains unresolved. Currently, there are many different devices in the world, from cheap and simple to expensive and technically complex, that allow one to measure the force of a blow in martial arts. Moreover, the measurement results of all manufacturers, as a rule, differ significantly, although they all claim to have correct measurements. Amateurs, fans and athletes continue to argue “who has a stronger blow”, do not trust the results of any strength meters (not without reason) and many have already come to the conclusion that such measurements are not possible at all.
Why does this happen?
The most common sensors used to measure impact force are strain gauges, piezoresistive and piezoelectric force sensors. All of them are highly accurate and are actively used to measure the force of impacts in industry and production, since they were developed for these purposes.
By measuring the impact force using these sensors, we ultimately measure the force generated by the impact and try to interpret it as the desired impact force, which, according to the laws of physics, is determined by the elastic properties of the target and the striking limb, as well as their size, shape and relative speed of movement. Calibration of such meters is possible only for bodies that have the same properties, dimensions and shape, which makes their use in industry possible. In sports, there are no calibrated striking limbs and calibrated blows. Thus, even considering a blow as a collision of two bodies (impact limb and target) with certain properties, shape and mass, we are not able to carry out an unambiguous calibration. The blow is much more complex and lengthy than a simple collision. Therefore, having only the shape of the shock pulse and not having full calibration, it is impossible to obtain correct results when measuring the force and energy of the impact using strain gauges, piezoresistive and piezoelectric force and pressure sensors.
Amusement rides often use spring structures. These designs are only suitable for measuring static forces, or, in extreme cases, shocks, since when such a meter is struck, an opposite elastic force arises (proportional to the amount of compression of the spring), which radically changes the biomechanics of the impact. With a sharp blow, the athlete can easily get injured.
For the same reasons, sensors that use liquid or gas pressure to measure force are not suitable. The biomechanics of the impact is disrupted here due to the elastic buoyancy force that occurs during the impact. Calibration is also not possible for the same reasons.
Thus, the disadvantage of the known solutions is the unreliability of the data obtained, since instead of the impact force, the forces arising during the impact are measured, and according to the laws of physics, they are determined not only by the biomechanics of the impact, as we would like, but also by the elastic properties of the target and the striking limb, and also their sizes and shapes.
I would also like to emphasize that in the vast majority of known cases, the designs of the meters greatly change the biomechanics of the blow, which is unacceptable, since this negatively affects the execution of the athlete’s blow. But even if we choose some ideal target as a target, we do not solve all the problems, since we will still have to “calibrate” the limbs of all athletes, which is impossible. And vice versa, imagining that all limbs are the same, we see that the force of the blow will depend on the rigidity and weight of the target. Even theoretically, the force of a person’s blow on a freely suspended punching bag weighing 8 kg cannot exceed 400 kgf. If you hit a suspended metal ball the same weight, we can easily get 4000 kgf. Hence the conclusion: The pursuit of record-breaking blows will only lead to designs of force meters with hard and heavy targets that test your bones for strength and the winner will always be a specialist in breaking stones. Let's summarize:
It should be recognized that the idea of measuring the force of an impact and taking this parameter as the main characteristic of the impact was initially erroneous and the impact energy should be chosen as the main parameter characterizing the force of the impact. In martial arts, the main task is to transfer maximum energy to the target when striking, this determines the effectiveness of the strike. I think the boxers will support us. To ensure that the measurement results are completely unambiguous, we select the kinetic energy of the target after the impact as the measured impact energy. The target, of course, must have physical properties (mass and elasticity) that do not violate the biomechanics of a particular type of strike, and must move freely in the direction of the strike. For boxers, for example, you can take punching bags from famous manufacturers, which will, firstly, eliminate the problem with biomechanics, and secondly, any manufacturer will be absolutely confident in the readings of their device, especially since with a correctly chosen scheme, calibration is not required at all.
I also propose to introduce two additional parameters that not only characterize the force of the blow, but also make it possible to evaluate the quality of the blow and the correctness of its application.
As these two parameters, I propose to choose the maximum force value recorded during the impact (impact) time and the impact (impact) time itself.
Additional parameters, which, although strongly dependent on the physical properties, size and shape of the target and the striking limb, under identical measurement conditions, that is, under the same weight category athletes, with the same type of blow and the same target, will be able to characterize such qualitative characteristics of the blow as sharpness and power. For example, with the same impact energy, a sharper and more powerful impact will naturally be one that has a greater maximum force and a shorter impact time.
By choosing impact energy as the main parameter, we practically eliminate the dependence of the measurement result on the properties, size and shape of the striking limb. More precisely, this dependence becomes an order of magnitude less pronounced.
IN physically this dependence is explained by the fact that part of the impact energy goes to deformation of the target, and losses kinetic energy during an elastic collision of two bodies, they are determined by the coefficient of recovery, which in turn also depends on the elastic properties of the colliding bodies, on their shape and mass. But the deformation energy relative to the impact energy is insignificant. Of course, the error in measuring weak impacts will be large, but no one is interested in them, since they are considered unsuccessful. As you can see, the measurement accuracy can be easily increased by choosing a rubber impact receiver as a target, which has a recovery coefficient close to unity, but this is more relevant for weak impacts, and for strong ones, the main thing is not to disturb the biomechanics.
I can offer three, in my opinion, noteworthy ways to determine impact energy.
The simplest way to measure impact energy does not require any equipment at all. It is enough to know the school course about kinetic and potential energy, as well as its conservation. To measure the impact energy, a target of known mass “m” is mounted on a sufficiently long suspension (for accuracy) and the amount of deflection of the target after the impact along the vertical “h” is measured. The impact energy will be equal to mgh (g-gravitational acceleration). In this way, it would be possible to measure the impact energy even before our era, and with fairly high accuracy, for example, the impact energy Olympic champion in fist fighting, the mathematician Pythagoras, who lived more than 2500 years ago, not to mention the boxing champions of the last and the century before last.
By the way, this quite effective, visual and accurate method can now be used to set Guinness records, which, as a rule, are recorded in big hall to a wide audience.
For the end of the last century, a method that would measure the speed of a target after an impact using a device that uses the Doppler effect during the propagation of ultrasound would be suitable. If the circuit is correctly selected, calibration is also not required here (Patent registration number 2006130981).
By far the most best option– use of precision biaxial or triaxial integral accelerometers to measure the energy and force of impacts (Patent Registration Number 2006130906).
The advantage of this method is that strikes at the target can be delivered not in a specific direction, but in any direction, except for strikes from above. Although, using a different design, it is possible to measure the energy of such impacts.
By the way, the impact force (as an additional parameter), unlike the designs known to me, is measured using this method in a really unambiguous and very precise manner (and not in some kind of conventional units, but in kg-s or newtons). But I want to emphasize once again - do not attach much importance to this parameter.
This method allows you not to lose measurement accuracy even in the case of a quick series of strikes, when the target sways and does not have time to take starting position. This allows you to sum up the energy of impacts with high accuracy and correctly assess the physical fitness of athletes. For example, in definition mode physical fitness The athlete is simulated in a boxing match with 3 or 12 rounds of three minutes each with a one-minute break. By summing up the energy of blows during a fight, one can easily assess the physical form of an athlete.
Integrated accelerometers with a digital output can be used as accelerometers, the high linearity and sensitivity of which will allow you to do without additional calibration. In the case of choosing accelerometers with an analog output, calibration is also very simple, since during the measurement process g - the acceleration of free fall - is constantly calculated and it becomes possible to organize a self-calibrating system.
Thus, the proposed method solves the problem of reliability of impact force measurements in combat sports. The declared solution, in addition to accuracy, ensures the manufacturability of measurements and resolves the issue of assessing the physical form of an athlete.
Using this method, even in a thousand years we will know “who had the strongest blow,” and not argue about it.
Football! Football! The fans are screaming - goal! There have always been serious passions around this game. Millions of boys all over the world have tried and are trying to be like their idols. Football sections and schools never lack people who want to study. The guys try to surpass other players in punch strength and speed. But how can we determine the force of hitting the ball and its flight speed?
Adidas Snapshot to measure impact force: how it works
The pioneer in terms of measuring the force of a ball hit and the speed of its flight was the Adidas company, which introduced the Snapshot program in 2013.
The application was available only to owners of devices based on the iOS platform, but, nevertheless, aroused keen interest among football fans. Subsequently, the development of the program was stopped, as “smart” balls appeared on sale, which, thanks to built-in sensors, measured speed much more accurately.
Using the application is very simple. To do this, you need to calibrate the size of the ball on the monitor. Next, the recording of what is happening begins. The player hits the ball. As soon as the ball stops moving, the recording stops.
It is necessary to mark its initial and final position on the screen. Based on this data, the program measures the distance traveled over a certain time and calculates the speed. This is exactly how footballer Gareth Bale demonstrated it in the commercial.
The program included some pretty interesting features:
However, the development had shortcomings. When Gareth Bale's hitting data became public, many people were able to surpass his results and proved it with their videos. This situation called into question the effectiveness of the software. This led to the abandonment of the use of video analysis to determine the force of the impact and the speed of the ball.
Other ways to find out the force and speed of an impact
If programs on iOS and Android platforms can still be used for amateur football, then for serious competitions they use equipment of a different class. These include sports radars.
These devices, according to manufacturers, successfully cope with their task. Their development has been going on since 2008. Manufacturers' assurances can be trusted, because for calculations, it is not video recording that is used, but information from sensors that make it much more accurate.
Sports radars on the market are represented by several companies:
- SportsSensors.
- Supido.
- PocketRadar.
The most correct and reasonable solution for calculating the impact force would be to equip the sports equipment itself with sensors. Agree, if there are sensitive sensors inside the ball that immediately at the moment of impact measure its force, and during flight calculate the speed - this is much more productive and accurate. This is exactly what Adidas did when the shortcomings of their mobile program were revealed.
The company released a smart ball, miCoach SMART BALL, which became available for purchase in 2014. However, its price of $300 scared off potential buyers. 
Reference! Now the price has dropped to one hundred dollars and has become comparable to the cost of top ball models.
The device has the following characteristics:
- classic size five;
- twelve sensors;
- The battery capacity is sufficient to hit the ball 2000 times, and recharging lasts sixty minutes.
Five of the most powerful football kicks
Football history stores data on many strong blows which successfully hit the target. The authors of some of them are listed below.
David Beckham
Back in 1997, the legend of the Manchester United midfield, as well as the England national football team, drove the ball into the Chelsea goal at a speed of 156 km/h. It was so lightning fast that the goalkeeper did not have enough speed to react and intercept the ball.
Cristiano Ronaldo
Cristiano Ronaldo's football career is still far from over, and he already has many individual and club trophies to his name. He has a lot of goals to his name. Like Beckham, Ronaldo specializes in free-kicks. But his most powerful shot came during the game. The ball reached a speed of 185 km/h. 
Roberto Carlos
This player from Brazil for a long time retained the title of football player with the most powerful blow. During the Confederation Cup, he scored a memorable goal against the French team, performed with great force.
From a distance of 35 meters, Carlos took a free kick. He was so strong that the goalkeeper could only follow the ball with his eyes - he simply did not have time to jump.
With what force does the Earth attract an apple hanging on a branch? You say, with the gravity of this apple. But Newton didn’t know this when he was sitting under the apple tree. The unfortunate discoverer also did not know with what force the falling apple would apply to his head. In fact, the fact that Newton discovered his great law of attraction after the fall of an apple is just a myth, a guess, a legend. But that's not the point. Sometimes we have the following questions: “with what force does a boxer hit a punching bag or a person?”, “how to determine it?”, “what does it depend on?”, “how to survive in a car accident?” and finally, “how hard did the apple hit Newton?”
An apple hanging on a tree is actually attracted to the ground by the force of its gravity. This force is constant in time, that is, it does not change, and is numerically equal to the product of the mass of the apple (for example, 0.2 kilograms) and the acceleration of gravity (about 10 m/s*s).
That is, we get a force of 2 Newtons. This is exactly the force that needs to be applied to hold our apple in our hand.
To find out the acceleration of gravity, you can throw a body from a high tower and calculate from kinematic considerations the speed with which the body picked up speed as it fell. This is what Galileo did in his time. The formula for gravity can also be derived intuitively: than more mass apple and the greater the speed with which the apple, falling, gained speed, the greater its gravity. So, we've dealt with the hanging apple. Now consider the force with which the apple hits Newton's head. For clarity, let's move on to another situation, and then return to the scientist.
The boxer decided that he had trained his fist enough and hit the concrete wall with some force. The next moment, he doubted his fists as he experienced searing pain. Then the boxer puts on his gloves and hits the wall again, and with the same certain force. This time he felt almost no pain. You say, the gloves softened the energy of the blow, or maybe the force... So what exactly? Gloves cannot reduce impact energy (in general, they reduce it, but not significantly). They only reduce the force of the blow, and according to our Newton’s 3rd law, it is exactly equal to the force with which the wall pushes the boxer’s fist back. This is the power we need. How did the gloves reduce the impact force? Due to the fact that they “smeared” or extended the impact in time. Gloves increased the time of fist contact with the wall. Without them, the contact time was several thousandths of a second less than with them. But these milliseconds are enough for the contact time with gloves to be several times longer than the contact time without them. Let it be 5 times. Then the boxer will hit the wall 5 times weaker and experience 5 times less pain. Naturally, I am talking about the average contact force, because in fact the impact force first increases and then decreases. Let us intuitively derive a formula for calculating the impact force. The greater the speed with which the fist moved before the collision, the greater its mass and the shorter the time of contact with the wall, the greater will be the average value of the force with which the fist hits the wall. We have just derived Newton's 2nd law in general view. This formula looks like this:
The numerator is the difference between the speed of the fist before and after the impact. In our example, the fist then stopped, which means that the speed V 2 will be equal to zero. From our formula it is clear that hitting a concrete wall is more painful than hitting a wooden wall (after all, the contact time of a wooden wall is longer, therefore, the denominator of the fraction is larger and therefore the recoil force is less), and that you should not run barefoot on a concrete floor (after all, in this case load on knee joint several times higher than when you run on a wooden floor in shoes). I will warn you: if you run barefoot on concrete or brick, you will wear out your knee joint and problems will begin. This should not be done even in slippers. Shoes with thick soles are better. I tell you this from my own life experience.
Returning to Newton and the apple, let's estimate the force of the latter's impact. Falling from a height of 3 meters, an apple will have a speed of about 8 meters per second before impact. Let it fly off in the opposite direction after the impact at a speed of 2 meters per second (with a “–” sign once in the opposite direction). And let the contact time be 0.004 seconds, that is, 4 milliseconds. This time can be measured using a high-speed camera. Then, according to our formula, the force of the apple’s impact will be 500 Newton, which is 250 times greater than the force of attraction of the apple to the Earth. It looks implausible. It seems that such a force will simply crush the unfortunate scientist. But having accepted the fact that this force acts on his head for only a fraction of a second, what was said becomes more realistic. From all this we can conclude: do not sit under apple trees.
From the above it follows: the shorter the contact time in the impact, the greater the impact force. Therefore, in car accidents, those who sit in the rear seats or whose airbag deploys are luckier, because in this case they will slow down for a longer time and the force of the impact will be “spread out” over time.
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08.08.2018
First stage: Speed test✔ ️
Impact force consists of several parameters, one of which is speed. Even if you have a stone fist, a hard hand and a mass of 90 kg, if you hit slowly, it will be of little use. And no, we are not talking about the fact that the enemy will be able to dodge the blow due to the low speed - this is understandable, but even if he is motionless, the blow will be weak. A simple example: imagine a mannequin standing in the middle of the road. This dummy has two opponents: one is large and menacing - Hummer, and the second is small and not dangerous at first glance - Matiz. Only the Hummer will travel at a speed of 20 km/h, and the Matiz at a speed of 100 km/h. Who will cause more damage to the mannequin? The hummer will only kick the dummy, which, God forbid, will bounce half a meter. But it’s scary to even imagine what Matiz will do.
That is why it is very important to know whether your strike is fast or not. For this we need tennis ball. We take the ball in the non-hitting hand, hold it in a fist and extend it straight in front of us, after which we bring the hitting hand to the chin and wait for the command. As soon as your wife, brother, matchmaker or cat says: “Start!”, you immediately unclench your fist and at the same time “shoot” with your striking hand and catch it. The first rule: the ball must remain exactly on the line on which you released it (otherwise you can cheat). Second: it should not fall lower than 7-10 cm. If you manage to catch the ball, you have excellent hitting speed! Let's move on.
Stage two: Testing explosive power✔ ️
If everything is quite simple with speed, then the parameter of explosive power is not clear to everyone. Let's try to explain simple example: Imagine two men whose impact speed at the end point is 100 km/h. In this parameter they are equal. But there is another parameter - the speed of reaching these 100 km/h. For example, the same Matiz and Hummer can (if they try, of course) reach 100 km/h, but they do it in different periods of time. For how quickly you reach your maximum speed and answers explosive force. Some people will need 1 second to strike with a final speed of 100 km/h, while others will need 0.7 seconds - believe me, this is a significant difference! After all, it depends on tenths of a second whether the opponent will fall from your blow or react and dodge. Let's start measuring!
We are sure that you know about machines that measure the force of impact - they are located in every park and shopping center. With this method you can measure the explosive force and power of your strike for free! We will again need a tennis ball and 5-10 minutes of training. We throw the ball into the air and hit it with all our might, after which we measure the result. If the ball flew 5-10 meters - low explosive force, 10-16 - medium, 16-25 - high. Accordingly, after a month of training, you can check whether the explosive power of your blow has increased - we record the result and try to improve it. Let's move on to the third and final stage.
Third stage: Checking the overall power of the blow✔ ️
As we have already said, impact force is a complex and rather complex concept. Many methodologists still argue about what components it consists of. We are as final stage To measure the total power of the strike, we will use the method that Airborne Forces fighters use in the field (during training). We take a plastic bag (transparent, with handles), hang it by the handles using two threads, stand in a stance and strike exactly at the center of the target. If you have good speed, explosive power and know how to put your full body weight into your punch, you will break the package. But there are several important nuances here!
The blow must be extremely straight and not go “down”, otherwise the bag can simply be torn off. If the bag falls off the handles, the test has not been passed. But if you passed the two previous tests well, then last stage- a matter of skill and a few damaged bags.
After going through all 3 stages, you can be sure that your strike is no worse than that of a boxer!
