Speed or Strength?

[Tim McMichael]

The bottom line for my argument is that your speed provides the potential for your vault. Your technique actualizes the potential and your strength helps you execute the technique.

The only thing I would add to that statement is this:

The bottom line for my argument is that your speed provides the potential for your vault. Your technique actualizes the potential and your strength ( adds energy to the vault ), and helps you execute the technique.

The point I am trying to make is that my amendment is an explanation of an effect and not a cause. I think that your theory is adequate to coach any vaulter to go as high as their potential will allow. The important thing is that they use their strength. What we believe the result of that cause to be is much less important.

I believe my theory to be correct because it explains the phenomenon more inclusively. It is an addition to your theory, and not a contradiction of it. I will absolutely concede that speed is by far the most important source of energy. You can stand at the box and pull and swing as hard as you want and not get an inch off the ground.

[jumpbackin]

[quote="Tim McMichael"]I got this coaching technique from a snake-handler I saw on T.V. He had been bitten something like fifty times, and the reporter asked him if it made him angry at the snakes. He said: “No, I’m supposed to be the expert here. The snake is doing the best it can with the only tool at its disposal, which is instinct. I’m the one with the capacity for abstract reasoning. If I get bitten, it’s my own fault.â€Â

[altius]

You are well on your way to sainthood Tim! - sadly I am probably going to go in the other direction! I would simply say that many more folk seem to post their thoughts on PVP as statements of fact rather than as genuine questions seeking enlightenment. There have been some superb posts on this topic - especially by the people I mentioned - but still there are those who either do not read them or do not understand them but who continue to dispute what has been said by people who I believe to be experts in their field.

If PVP is to be simply a chat site where anyone can express any opinion - no matter how inane - that is one thing. However if the objective is to advance our understanding of this great event I suggest more folk should put their brains in gear before they put their fingers to the keyboard. Now THAT pompous! A pity - I like the sound of Saint AL.

[vault3rb0y]

I completely agree... i know very well im not an expert and i dont assume to be. Thing is, there are very few kenisiologists/ exercise physiologists/ pole vaulters on this site... and these are some of the people who can not only give the correct advice, but prove why it is correct. When i say my opinion, if anything it is stating how i feel right now, but ive only been pole vaulting for 3 years and no matter how hard ive thought about it, for every day of that 3 years, i will always have something to learn. I think that goes for everyone.... and the only way to respect what you hear on this site would be a ranking system or something.... lol to let people know how much they know about vaulting compared to others. This would take way too much time and effort, and would take away from the experience of PVP. The best thing we can do, is to ALL post with open minds and opinions. Pole vaulting might not ever be a concrete event, in which the exact correct way and efficient way to do soemthing is written out. Sure, we can guess at it, but only to a point, then it becomes a science beyond what the average person can get their minds around (myself included). So look and learn, assume and be proven wrong, post how you feel and allow others to change how you feel... because in the end all anyone on this site wants to do is help each other pole vault higher .

[euroeva]

Energy is transferred. KEnetic energy = potential energy while in the air.
so the faster you run the higher you should technically go. However, I BELIEVE (not a fact altius), that you still need technique to go as high as you potentionaly can. so
KE=.5mv^2
PE=mgh

.5mvf^2=mgh

mass=your weight
vf=final velocity (speed)
^2=squared
g=gravity
h=height (the maximum you can potentionally reach)

Anyway this is what i learned from physics this year. They actually used a pole vaulter to explain it.

[master]

The equations work well as a starting point. Then the factors like center of mass and height of top hand at take off come in to play. And then you get into the issues of what you do with your body at different times in the vault (changing the location of your COM; applying forces with a different lever arm). The more you know, the more complicated it gets.

The following web page does a good job of describing the fundamental equations and considerations of the vault (http://pukashell.net/kimo/polevault/physics.html). The author also provides info from others sources. You all might find it interesting (even though I think I mentioned this in another post during the past year).

Now I'll go off on a tangent, if for no other reason than it is yet another example of how we can be connected by who we know. (You know, the idea of 6 degrees of separation). When I first read Kimo's page, I felt one of his diagrams could be improved from an engineering perspective. I wrote him and sent an image that was a modification of his original. He replied and agreed with me and changed his page. A few months later, during a discussion with my son Eric, I mentioned this to my son. During the discussion Eric thought some things sounded familiar. We went to the computer and viewed Kimo's pole vault page and from there, Kimo's bio page. Eric was able to confirm he knew Kimo from some classes in grad school. It's a small world and getting smaller by all of us using the internet to share thoughts and videos, and sharing the knowledge and experiences from our own lives.

- master

[PVstudent]

In regard to PVP, the discussions on technique and strength I think have gone a little adrift.

Pole vault as far as I'm concerned is not all about speed. It is still the the 6 essential s's, Sprint, Spring, Swing, Spiral , Spring and Soar!

The vault process is performed in a continuous Strong Smooth Sequence to produce Successful Safe Springing upwards with the assistance of a Springy pole used Skillfully to project the vaulter Skywards to Sail over the crossbar!

Sprint = Running fast with precision, acuracy and efficiency of pole carriage and placement.

Spring = Leaping high from the gound and giving the pole pendular motion about its tip axis in the vaulting box.

Swing = Supplying synchronised muscle action timed and directed to produce pedular motion of the vaulter on the pole whilst maintaining pendular motion of the pole towards the vertical plane of the bar.

Spiral = Continuation of the swing from the tranverse axis to twist along the vertical longitudinal axis of the recoiling pole to complete the vaulter inversion with a half twist.

Spring = Continuationof the upward projection of the vaulter by means of a downwardly directed pull and push by both arms and then one arm only until contact with the pole ceases.

Soar = Flight with parabolic path of the vaulters centre of gravity in which the vaulter's limbs, head and torso are oriented with respect to the vaulter’s centre of gravity in a series of actions that enables the bar to be passed over without it becoming dislodged.

I am still surprised by the difficulty some reader's of PVP appear to have with Newton's Laws, especially the operation of the action reaction principle when two bodies (masses) are in contact.

From some of the responses in regard to adding energy (doing work) whilst in the pole support phase (vaulter off the ground and prior to pole release) they appear not to accept that muscular work performed by the vaulter can add energy to the system.

I contend that the centripetal (centrifugal) force due to the vaulter's swing, speed and the angular displacement the vaulter's body goes through, must equate to work. For the swing to occur some torque must be applied and it must act through an angular displacement if swing occurs! If a torque is applied and then as a result an object(mass) undergoes rotation about an axis work will have been done. The amount of work done equates to the torque multiplied by the angular displacement and is the energy supplied in the case of the pole vaulter's swing generated through muscle action. (Force x Displacement = Work : Torque x Angular displacement = Work).

I suppose it is difficult to accept that the forces/torques created by the vaulter's muscles has an effect on the earth that is returned in equal size and opposite direction whilst contact between these two objects exists.

To an external observer of the pole vault (coach, other spectator) the acceleration of the earth is infinitesimally small relative to the larger accelerations observed in the vaulter and pole. Because the vaulter is animate (one hopes that this remains so throughout the vault!) he/she is capable of converting chemical energy into muscle action that can do work on the pole and hence the earth whilst in the pole support phase.

Once pole release occurs any muscle actions on the part of the vaulter will be viewed by the external observer as producing action -reaction movements of the vaulter's body segments about the vaulter's centre of gravity. Since there is no direct contact with the earth any action of a body segment will be matched by a proportional but oppositely directed reaction in some other body part/s. Note also that the path (trajectory) of the vaulter's centre of gravity cannot be changed once contact with the pole is released.

The flight path of the vaulter's centre of gravity cannot continue to be in the same straight line and direction during the airbourne phase of the vault (the flight after pole release) because of the action of gravitational force which operates on the vaulter at all times in both the grounded and aerial phases of the vault.

The laws of conservation of energy must apply throughout the pole vault from first pole pick up to the vaulter's victory lap and well earned sleep! (Energy is neither created nor destroyed merely transformed whether here on earth, in the depths of space or the furthest reaches of the universe).

No vaulter will ever achieve light speed and since it will only be at that speed or higher there might be some question about how the conservation laws apply! I do not wish to speculate on the operation of the conservation laws at the quantum level.

However no one needs to take my assertions above seriously! However if any pole vaulter, or coach for that matter, finds that Newtonian Laws, correctly interpreted, do not practically operate in human motion at all times and in all places on this planet I want to know about it! It will be news to me and others who want to understand how to help pole vaulters to jump to great heights safely.

If you are still not convinced that it is both possible and desirable to add energy in the pole support phase of the vault refer to the following scientific articles which show that successful pole vaulters ( males and females) do indeed ADD energy during the pole support phase. The studies clearly show that at the peak of their flight trajectory some successful (if you consider Olympic Finalists to be successful vaulters) pole vaulters have more energy at that point and time in the vault than at the takeoff when the takeoff foot toes break contact with the ground.

Even some less than elite level pole vaulters have demonstrated they are able to add energy to the pole after takeoff as shown in the results of the second study cited below.

If this is true where did the additional energy come from? It cannot have been supplied solely by the the kinetic energy generated in the approach run added to the the potential energy due to the vaulter's centre of gravity height above the ground and body segment rotational kinetic energy at the instant of takeoff.(total energy at takeoff = run up kinetic energy transfer to pole + potential energy due to vaulter's position of C of M + vertical upspring energy + vaulter's body segment rotational kinetic energy + potential energy of the pole C of M + rotational kinetic energy of the pole). I understand some energy will have been lost as friction induced heat, sound and vibration due to wobbling tissues in the vaulter due to impact induced shock waves.

Hopefully someone can account for the observed results reported in the studies cited below to explain where the aditional energy that was measured came from if it was not generated by the vaulter!

Schade F., Arampatzis A., Bruggemann G-P., Komi P.V. (2004) Comparison of the men’s and women’s pole vault at the 2000 Sydney Olympic Games. Journal of Sports Sciences, 22, 835 – 842.

Arampatzis A., Schade F., Bruggemann G-P, (2004) Effect of the pole – human body interaction on pole vaulting performance. Journal of Biomechanics, 37, 1353 – 1360.

[altius]

Quote "Pole vaulting might not ever be a concrete event, in which the exact correct way and efficient way to do soemthing is written out. Sure, we can guess at it, but only to a point, then it becomes a science beyond what the average person can get their minds around (myself included)."

The above sums up much of this discussion on this and other topics on PVP. Unfortunately pole vaulting iis not like a work of art , a piece of music or even a bottle of wine where anyone can state quite accurately and categorically - i dont like that, or "In my opinion ..... ".

As PV Student suggests there are scientific principles which can be applied in the pole vault and in 1985 at the European coaches congress in Birmingham England, Vitaly Petrov described how these principles were being applied to pole vaulting. For the first time a critical analytical methodology had been used to develop a technical model for the pole vault. Petrovs first protege, Sergei Bubka then proceeded to demonstrate the application of these principles as he set numerous world records, so we have termed this the Petrov / Bubka technical model.

The Petrov/ Bubka model is like a multi stage rocket with energy being applied smoothly throughout the vault to punch the vaulter into the space above the bar.

Folk who believe that it is impossible to put energy into the pole after you leave the ground clearly believe in the Cannon model of pole vaulting where all the energy has to go in to the pole in a single explosion at take off. Unfortunately that model leads to all kinds of problems, including injury and death for some athletes who have employed it- as it would have to the passengers in the projectile HG Wells proposed to fire to the moon from a huge cannon, at the end of the 19th century.

Both Petrovs presentation and an article dealing with the idea of a multi stage rocket - which in essence represents agapits continuous chain model, can be found on the Beginner to Bubka website - if of course you can find that! However as Baggett would say - waddever!

[master]

Well gents, I read most of what is posted here about technique and training. I try to keep an open mind, but I admit I do apply a filter at times. I feel comfortable enough in my knowledge of the vault to distinguish between potentially useful new or different views and just plain lack of understanding of physics and mechanics.

My main concern is how to get this old body of mine to do what I learn would be good to do! Or, as a friend has said "what is technically desirable must be physically possible". I keep trying but I'm beginning to believe the old saw "Ya can't teach an old dog new tricks."

- master

[Tim McMichael]

PV Student

Thanks so much for that post. Awesome analysis and explication. Please send me a message with your name so I can give you credit if I use this in the future.

[baggettpv]

Good to have you back!! but lets stay in the coaches forum with the same topics. I have one there on Teaching experience. Seems as the not many coaches are teachers and few if any from the Psychomotor fields (PE, Vocational, Music or Art).

Rick Baggett

[jumpbackin]

Folk who believe that it is impossible to put energy into the pole after you leave the ground clearly believe in the Cannon model of pole vaulting where all the energy has to go in to the pole in a single explosion at take off.

Now I understand, Altius, you don't actually read the posts you're commenting on. You must just skim them and develope an idea of what the posters must be saying.

I don't think anyone in this forum, make that the world, believes you can't add more energy to the pole after you leave the ground. That's one of the main objectives of pole vaulting. Put as much energy as possible into the pole then take it back during the recoil.

My argument is once you leave the ground there is a limit to how much energy can be transfered into the pole. That limit is set by the vaulters reach, speed, body weight and levers. Strength is one of the tools for transfering the energy but doesn't add to it. Talk about having to restate the same thing in 20 different ways!

FYI I have changed my mind. I now believe that once the pole begins to recoil, tha vaulter can add more energy, in that he is now able to push off the ground through the pole.