Here's one to peruse, why not a longer pole?

[Barto]

It just seems to me that as long as a vaulter is connected to a pole -which is in turn connected to the ground - it is possible for them to apply force to that pole no matter how fast they are moving....

I would also appreciate it if you could tell me at precisely what point you believe a vaulter of say Bubka's calibre finishes applying force to the pole.....

Oh and does this point at which the application of force ends, vary with the performance level of the athlete? In other words, if they are not moving very fast on the top of the pole can they apply force to the pole or not?

Okay-

First point, it is not possible to apply force on a body in motion if that body is moving faster than the impulse you are trying to push it with. In other words, as the body passes above the elbow joint on an elite vaulter's jump it is traveling faster than the elbow and shoulder joints can be employed to apply force with. It is like trying to reach out and push a car as it drives by you at 50 kilometers per hour.

Second point, there are only two sources of force a vaulter can employ to add energy into the pole/vaulter system. The velocity of the run multiplied by the mass of the vaulter is one source. The other source is the chemical energy stored in the core muscles of the body (from takeoff leg hip flexor up through the abdominals and muscles of the top hand side chest.) This chemical energy is released through myotatic reflex or stretch reflex after takeoff when these muscles stretch and then "snap back" with much more force than a person could voluntarily contract them. This results in the swinging of the trail leg. Sooooooo.....an elite vaulter finishes putting energy into the system when the trail leg swings past approximately 195 degrees or 7 o'clock. This point is determined by biomechanical factors which vary from athlete to athlete (height, leg/torso ratio, etc.) After that point, everything the vaulter does is all about CONSERVING the energy already put into the system, not generating any new energy. There are certainly things that an elite vaulter does that make them much more efficient at conserving this energy and applying it to a higher vault, but there is no "new" energy put into the system.

Third point, this is really an extension of the first two paragraphs, but the short answer is "yes" if a vaulter is moving slow enough off the top of the pole then it is possible to jump higher by pushing down on the top. This is not happening at the elite level, but at the novice level it is possible.

Hope I didn't get too technical, but then again this is the pole vault.

Barto

[Mecham]

So a new question comes up. We know that you add energy throughout the vault. How do you add more and more and more? If bubka had enough energy to jump over 4.5ft over his grip, there could be a way to make that 5, or even 6 feet. How does one create more energy?

[vaultwest]

HERE IS MY 2 CENTS
If you look at the evolution of the fiberglass (bending ) pole, what one notices is that the biggest advances have come in pole construction that allows the pole to be bent more while maintaining safety and adequate return of energy to the vaulter as the pole returns or un-bends. As these improvements were made, and the biggest was Herb Jenk's invention of the spiral wrap for hoop strength, the poles were able to be bent more, return more of the energy to the vaulter and remain safe. This enabled grips to go up. I will not go into all of the technical reasons for this but I think it is pretty staright forward that these newer poles are safer and allow for higher grips than the poles of the past.

Thus I believe the next advances for the vault in terms of pole technology will be new materials or construction methods that allow vaulting poles to not only be bent past the levels we see now while also keeping those poles safe when bent that much and still able to return the energy properly to the athlete as the pole returns.

[altius]

Thanks Barto - I am beginning to understand - but 'myotatic stretch reflex'?? You mean like when you pull your index finger back as far as it will go and then release it against someone's head?? ( Way to go Mecham!!)

So in your view 'ordinary' vaulters -whoever they may be - CAN continue to put energy into the pole because they are not moving fast enough - Right???

So at what performance level does this change?? How fast does the athlete have to be moving for them NOT to be able to apply force to the pole through the extension of the right arm/wrist and fingers?

You didnt specifically indicate at what point you believed Bubka stopped putting energy into the pole. However I assume on the basis of what you did write, that you believed that he could not/did not put more energy into the pole after he had reached the 7 oclock position - here I assume you mean when his body swings level with the chord of the pole?? Was his superior performance simply the result of those two elements of his technique?

Are you really saying that he did not/could not apply force to the pole after that point? After all he was still connected to the pole, which is connected to the ground, and his body was moving! What about the way he moved into the inversion - punching the hips up and driving the shoulders down towards the pad - could this not apply force to the pole - perhaps even maintaining the bend fractionally longer before it recoiled? Is this possible in your view? Or is he just conserving and redirecting energy as you suggest?

Now as elite athletes come off the top of the pole you said that it is an illusion that they apply force to the pole as the arm/ wrist/ fingers extend because their body is moving too fast for this to happen??

This all bothers me because having worked with some pretty good shot putters (release speeds 13 plus m/sec), having watched a few heavyweight boxers throw a right cross (speed??) and seen Karate experts break bricks with their hands (around 10m/sec), I suspect that their hands/arms are moving a fair bit faster than even Bubka was as he came off the top of the pole (Jagodin and Papanov estimated Bubka COM rising at 1.4 m/sec on one 6.01 jump they analysed). If this is so then surely a vaulter can continue to apply forces to the pole right up to the instant they lose contact with it.

The problem I am trying to deal with is that your argument suggests that the athlete's ability to apply force to the pole ceases when they swing - or preferably whip - to the chord of the pole. If you are right this has major implications for how we should teach and coach the event.

However I do not believe that you are right and I hope coaches out there dont accept your opinion because if they do they will be restricting the performance level of their athletes. Unfortunately I suspect we have reached a point in this discussion - only a side issue to the original topic -where we will get no further for as my old gran used to say 'a man convinced against his will, remains of the same opinion still'.

[maximus]

What made Bubka so good ontop of the pole was:
1. His ability to put his body in the perfect position to lose the least amount of force being applied to his body by the pole as the pole uncoiled.

2. His ability to time the final application of force to his body by the pole with an instantaneous, precise, and violent pull and turn that DID apply force to the pole (no matter how miniscule) and allowed for the extra lift that he got from the pole that most do not. I think that anyone who saw Bubka at his worst, as opposed to his best (which are all the clips on the internet) can agree that this final application of force, if not perfect, was not that impressive. When Bubka did not time this phase up correctly, he looked as normal as anyone.

The thing that I feel is lost in Barto's assessment of force application is that the effects of gravity and air resistance on the vaulter (Newton's 2nd Law) CAN be utilized by the vaulter by pulling and pushing when the vaulter puts his/herself in the proper positions through the course of inversion. No matter how miniscule these forces are in relation to the force being applied to the vaulter by the pole, the cumulative sum of them applied throughout the inversion phase by the vaulter putting him/herself in the correct positions and timing the pull and push correctly, coupled with an athlete such as Bubka loading an extremely large amount of energy into a VERY stiff pole through the approach, take-off, and swing DOES make a huge amount of difference off the top.

In relation to the original topic of this post, I think that if poles can continue to get more lightweight that would be a huge help, but also if they could get to the point where planting a 12.0 is like planting a 17.0 but stores energy and returns energy like a 12.0, but like many posts on this board, that may defy the laws of physics

[Barto]

Thanks Barto - I am beginning to understand - but 'myotatic stretch reflex'?? You mean like when you pull your index finger back as far as it will go and then release it against someone's head?? ( Way to go Mecham!!)

So in your view 'ordinary' vaulters -whoever they may be - CAN continue to put energy into the pole because they are not moving fast enough - Right???

So at what performance level does this change?? How fast does the athlete have to be moving for them NOT to be able to apply force to the pole through the extension of the right arm/wrist and fingers?

You didnt specifically indicate at what point you believed Bubka stopped putting energy into the pole. However I assume on the basis of what you did write, that you believed that he could not/did not put more energy into the pole after he had reached the 7 oclock position - here I assume you mean when his body swings level with the chord of the pole?? Was his superior performance simply the result of those two elements of his technique?

Are you really saying that he did not/could not apply force to the pole after that point? After all he was still connected to the pole, which is connected to the ground, and his body was moving! What about the way he moved into the inversion - punching the hips up and driving the shoulders down towards the pad - could this not apply force to the pole - perhaps even maintaining the bend fractionally longer before it recoiled? Is this possible in your view? Or is he just conserving and redirecting energy as you suggest?

Now as elite athletes come off the top of the pole you said that it is an illusion that they apply force to the pole as the arm/ wrist/ fingers extend because their body is moving too fast for this to happen??

This all bothers me because having worked with some pretty good shot putters (release speeds 13 plus m/sec), having watched a few heavyweight boxers throw a right cross (speed??) and seen Karate experts break bricks with their hands (around 10m/sec), I suspect that their hands/arms are moving a fair bit faster than even Bubka was as he came off the top of the pole (Jagodin and Papanov estimated Bubka COM rising at 1.4 m/sec on one 6.01 jump they analysed). If this is so then surely a vaulter can continue to apply forces to the pole right up to the instant they lose contact with it.

The problem I am trying to deal with is that your argument suggests that the athlete's ability to apply force to the pole ceases when they swing - or preferably whip - to the chord of the pole. If you are right this has major implications for how we should teach and coach the event.

However I do not believe that you are right and I hope coaches out there dont accept your opinion because if they do they will be restricting the performance level of their athletes. Unfortunately I suspect we have reached a point in this discussion - only a side issue to the original topic -where we will get no further for as my old gran used to say 'a man convinced against his will, remains of the same opinion still'.

I think we need to go back to even more basic pole vault physics. THE ONLY AND I MEAN ONLY FORCE that determines how high a vaulter can POTENTIALLY jump over his handhold is the velocity of the pole as it moves from takeoff to vertical. The only way a vaulter can generate this force is by his takeoff velocity and swing forces as he swings through the perpendicular plane. After this point, there can be no other energy added to the system. The forces that vaulters apply from this point on only serve to conserve the loss of energy from the system. Swinging up and forcefully pushing the hips up may be necessary and desireable parts of typical pole vault technique; however, they also serve to slow the pole's movement to perpendicular. They cause a loss of net pole velocity. This loss can be minimized through what we call good technique, but it is a loss none the less. You can not add more potential energy to the vault after swinging past ~ 7 o'clock. After this point the velocity of the swing begins to lessen and all the vaulter's actions become a matter of conservation.

As for the shot put or boxer analogies, they are not applicable to the pole vault for different reasons.

To use a weight lifting analogy, the shot put is much like the jerk. Large muscle groups are employed to take an object that is stationary relative to the muscles that are going to be employed to push against it and move the object out and away from the body. The pole vault is much like the snatch. Large muscle groups are employed to push against an object that is not stationary relative to the muscles being employed to push against it as it goes past. Saying one can push down against the pole is like suggesting that the weight lifter should be pushing up against the bar in the snatch.

The boxer analogy does not apply to the pole vault in that the boxer employs large muscle groups to "throw" his fist on the end of a double hinged lever (his arm). The velocity of the punch is increased by the mechanical advantage gained by the lengthening of the lever employed to throw the object. Pole vaulters do not have this mechanical advantage on the top of the pole.

Barto

[souleman]

So what I am seeing here is all of you don't think that a longer pole is ever going to be possible is that correct? Am I correct here with everybody's assessment for the answer to this question? Some have suggested that there is vertually no push off benefit in the 6.40 model. Is this because of the recoiling of the fibreglass pole? Many of you are not old enough to have seen Bob Richards pole vault back in the 50's. With out the aid of a fibreglass pole, Bob Richards vaulted over his grip regularly, and he also had an impressive push off at the top. According to most of the replys, I'll assume his push off was possible because he was doing these things with an aluminum pole that did not bend. Maybe altius has been right all along when he's said that the vault community has been more concerned about making the equipment work, and improving that equipment, rather than making the vaulter better. If my Dad the engineer were still alive, I'm sure he would talk about the impossibility of getting more energy out of a pole than was put in because of something called mechanical disadvantage. Mechanical disadvantage, If I remember my Dad's explanation of it correctly, is due to the forces of gravity. Therefore because of gravity's effect on the laws of inertia, as long as we are pole vaulting on this earth, we will never get more out of a pole than we put into it. In fact, we have to put more into it than we will ever get out of it. So the variable here is "US". What do we have to do and how do we get it done to hold/jump higher? I still would be interested to find out how fast a 180 pound object would have to move to make a 20 foot stick stand straight up in the air?Later................Mike

[SKOT]

i got an idea. how about we get a nice downhill runway, some elite vaulters, some super long poles and a speed trap and see what happens...

[altius]

Barto - I still cant get an answer to two questions I posed. At what level of performance does it become impossible for athletes to apply force to the pole as they begin to come off the pole - given that you stated that at some level they can do so. This is an important question that coaches need an answer to. Secondly at what point do you believe Bubka stopped applying force to the pole - is it as you state when he passed the chord of the pole?

These are related questions because I cannot see how Bubka stopped applying force to the pole when he passed the chord of the pole but a lesser athlete can apply force as they come off the top of the pole??

--------------------------------------------------------------------------------However even if I get answers to these questions, it is clear that Barto and I are not going to agree - so before it becomes disagreeable I would simply point out to coaches that if they accept his version of the biomechanics of pole vaulting, they will have to throw out Agapit's notion of a "Continuous chain" of energy input without any passive stages from take off until the athlete releases the pole. They will also have to ignore the Petrov/Bubka technical model which reflects that notion.

I am heartened by the thought that biomechanists have never contributed to the development of a new technique - at best they have come forward to explain the advantages of these technical models after they were developed by athletes playing with their event. Here the O'Brien shift in the shot and the Fosbury flop in the high jump stand out.

It is also interesting to note that in the early days of fibreglass vaulting biomechanists contributed to the misunderstanding of effective technique by encouraging vaulters and coaches to believe that an early pole bend - ie before the athlete left the ground was important. A myth that continues to this day to the detriment of many vaulters' performance. Finally I would point out that the notion of a pre jump take off was also poo pooed by biomechanists - this despite the fact that Petrov had described it in his paper presented in 1985. This position changed in 2002 when Bubka himself made it clear that he did in fact aim for such a take off all the time -even though he "only achieved it a few times".

Barto - may the force be with you always!

[Mecham]

I still think the idea of having a longer pole that can bend in more than one spot is a pretty sweet idea

[bjvando]

i heard theres some 'medicine' that can help you get on 18' poles.......

we should try theSan Francisco area, i hear they have good medicine......

[dj]

barto

i'm thinking along your line of thought..

the swing has more to do with the "height above grip" than sheer arm muscles.. forced movement is not as fast as "reflex" or what maybe should be called follow through.

someone should ask t-mack. he had a pretty good "push off" and looked to add a little "pop" kip.. to the vertical finish.. How did he do that?

the swing gets the body mass moving and it only takes a "tap" "flick" to help the moving mass "accelerate" off the top. so if "force" can be added this would seem to be the only way.

for example why can a shot-putter throw further from a glide than a stand? the 16 lb ball is already moving making it "lighter' for the wrist and fingers to add "force' with the speed of the "flick"

so maybe you and allan are both right... you have to have a great, fast, swing to add a "flick" from the top.

dj