ideal technique in the fiberglass vault

[dj]

PSS… confusion? Looks like the problem we are having is the "definition" of a "free" takeoff.
And our "picture" or descriptions are not adequate… a real "free" takeoff is an "action" (physics) and the result of that action. You can have a "free takeoff" and follow that with any "form", tuck and shoot or "swing" that you choose… that is dependent on other "actions" just following the FTO including grip, pole and takeoff speed.

Two vaulters can be "under" by 10cm, ie when I compared Tully and Bubka, have very similar numbers in horizontal speed, pole and takeoff angle, reach height etc BUT with one major difference! And that was resultant velocity…

Resultant velocity is what we have to view as a "free takeoff"… the "action" not the "picture" or the "out" or the slightly bent, not bent, negative bend, etc… a free takeoff is "a greater resultant velocity."
When Tully "felt" 3 to 4 inches out, fast with a high plant and a quick last two steps, his response to me was.. "I knew I had to swing like hell to catch up with the pole, ANY hesitation in swing fast and I knew I would go over the pit!"

That is the result of a "free takeoff".. changing the speed from horizontal to vertical, Resultant Velocity.

On the jump I posted from Youtube he felt that way.. yes he had a big tail wind… but he knew if he had a few more jumps like that in him he could have raised his grip on a slightly bigger pole and taken shots at 6 meters plus.

dj

[KirkB]

5. The vaulter must vigorously spring off the ground in a FORWARD/UPWARD direction. Note, the average reported take off angle of elite vaulters is 18 degrees, strong evidence that elite vaulters spring in a forward/upward direction and not directly upwards as professed by p/b advocates.

I don't think ALL "p/b advocates" insist on a "directly upwards" jump impulse at takeoff. There is no doubt amongst Petrovers that there MUST be an up impulse, but the angle at which you jump has never been explicitly specified by anyone - to my knowledge.

In my particular case, I know that I jumped UP higher than most, but at the same time, I believe that I also jumped FORWARDS more than most. In other words, I definitely had an UP IMPULSE, but not necessarily higher or lower than 18 degrees. I actually don't know my takeoff angle, because I never measured it.

What I do know though, is that my body posture was most definitely leaning forwards - actually to the extreme (even more extreme than what I normally recommend to most vaulters - especially those that "can't jump". So if I long-jumped at that same takeoff angle - and I've done this - I would fall into the sand pit flat on my face!

6. The vaulter should strive to move as continuously as possible over the take off foot during the take off., so the take off becomes a combined run off/spring off action.

If you're "running off" the takeoff instead of jumping, you're doing what is called the "Dial Model" or the "Drive Model". By your wording of "The vaulter should strive to move as continuously as possible over the take off foot during the take off", Dave, you even seem to be implying that you may be advocating a heel-toe action with your takeoff foot (even flat-footed?) rather than striking the ball of your foot down and springing up without touching your heel at all? Please clarify?

If that's the case, I consider that quite an inefficient takeoff action, fraught with energy leakage into the ground. Agree or disagree?

Kirk

[david bussabarger]

dj,
I assume that what you are saying is that if the vaulter executes a free-take off his/her take off velocity will be greater. I have already discussed this point with pvstudent but will do so again here. Note, I don't see how it is possibble to discuss the free-take off without considering the vaulter's take off point and at what point the vaulter begins bending the pole. After all the definition of a free-take off is delaying bending the pole until the vaulter is off the ground ( which is STRONGLY impacted by the vaulter's take off point ). Correct me if I'm wrong.
Several studies show that taking off under, hence not using a free-take off, dissipates take-off velocity ( the farther under, the more velocity is lost ). I find these studies problematical. 1st more than 1/2 of all 6m or better vaulters do not use a free-take off ( they take off under and begin bendinding the pole while on the ground ). So, if not using a free-take creates such a seemly hudge disadvantage, why do so many 6m vaulers succeed without one? My agruement is that take off velocity must not be as important as typically assumed. My theory is the key factor is how much penetration force the vaulter generates during the take off, which is not dependent on any specific take off point.
One has to realize that scientific studies can be misleading and even completely false. They are also subject to the same SIMPLISTIC standards of proof that all science is subject to. That is they must be proven empirically ( proven by observation of the real world or by experimentation ). Again, correct me if I am wrong.
As to the laws of physics and bio-mechanics,they simply rule out what is impossible but do not prove the possible. An anology here is that logic also rules out the impossible ( a logical contradiction is automatically false ). But you can create a logical arguement for a false premise. The greeks called this sophistry.

[KirkB]

I feel tuck and shooters are "created, being created" with short-slow run vaulting.. high grips, stiff poles and of course "force" bending at the takeoff in an effort to "penetrate" to the pit or force load the pole.

The "grip-and-rip" technique!

I agree that too many young vaulters are guided in this direction - unfortunately, to their detriment.

I think that the very confusion re PV models that we're discussing in this thread is to blame for this. If we could only apply physics and science to our event in an objective, revealing, universally-understandable way, and to the right level of detail, then we would have the foundation for moving forward with the advancements in PV technique.

I feel vaulting with speed, with an out, high takeoff , right grip and pole for the speed at takeoff and swing as fast as you possible can is the best most efficient way to vault.

I really appreciate you joining this thread recently, DJ. You add another perspective that puts it altogether - with stats and examples based on physics to back it up!

Kirk

[KirkB]

The 1st thing that has to be done is to agree on a definition of the term tuck/shoot. ... To make things even more confusing, some of these vaulters emphasize delaying ( Hartwig ) and some do not ( Pursely and Galfione ), but visually there is not much difference.

As previously stated, I actually don't care if a vaulter is tuck-shooting, as long as they're not PAUSING at the end of their tuck. IMHO, it's the TIMING of their tuck-shoot that indicates their efficiency on the pole. So if you say that Pursely and Galfione don't delay their r-b, then IMHO they're not the standard tuck-shooters that I think are inefficient in the raising of their CoG as quickly as possible. After all, if theirs is a continuous motion, then where's the energy loss?

So I would like to change your question re defining the term "tuck/shoot" from "what is a tuck/shoot?" to "is there a pause in their swing or tuck?". If there's no PAUSE, then no problem.

I have made this proposal in a number of different ways now on this thread, but I don't think we've reached a meeting-of-the-minds on this yet - even though we both agree that a Continous Motion Technique is more efficient than a Delayed Extension Technique.

Kirk

[KirkB]

When Tully "felt" 3 to 4 inches out, fast with a high plant and a quick last two steps, his response to me was.. "I knew I had to swing like hell to catch up with the pole, ANY hesitation in swinging fast and I knew I would go over the pit!"

That is the result of a "free takeoff".. changing the speed from horizontal to vertical, Resultant Velocity.

Yes!

I would temper that by saying "After a good quick stretch to the C without any hesitation whatsoever ...", but yes, that's it exactly!

And without saying it explicitly, I think Tully was implying that he COULD and he NEEDED TO keep swinging back PAST vertical, and extending upwards such that his extension was near-100% vertical, and the roll of the pole is what carried him horizontally over the bar.

You need to feel that you can "pull/extend like hell" - without any hesitation - and not stall out. That's what Tully was saying, I think.

DJ, do you agree that he was implying these additional points?

Kirk

[david bussabarger]

Kirk,
I basically agree with your point on tuck/shoot ,but , correct me if I'm wrong, even Hartwig didn't delay all the time. Also it is possible to delay at the end of a "piking " r-b action. I experimented with this idea in high school, but gave it up because I got inferior results.
In terms of the take off, it is possible to both move nearly contuiously over the take off foot and also spring off the ground ( i.e. a combined run off/spring off action ). Most elite vaulters do this by minimizing the gather action in the take off. This action minimizes the lose of kinetic run energy. You definately don't want to "settle" on the take off foot, which causes a great deal of kinetic run energy lose.
I stand corrected on the direction of spring and p/b advocates. Petrov himself talks about forward/upward spring. But Launder emphasizes springing vertically in his book and I have run into other p/b advocates on line that also emphasize this.
If you spring off the ground in a forward /upward direction you will naturally also gain some vetrical height as you do so. It is my view that this is desirable because vertical take off movement naturally produces rotation in the pole's axis ( if your springing action is correct there is no need to try to push the pole towards vertical with the arms during take off ). But if you generate too much vertical spring ( raise your c.m. too much ) as you leave the ground you will disapate (sp?) kinetic run energy ( the more you raise your c.m. the more energy you lose ). This is why you want to spring forward/upward not vertically.

[david bussabarger]

Kirk,
After some thought I think the tuck/shoot should be renamed the delay/shoot. What do you think?

[KirkB]

After some thought I think the tuck/shoot should be renamed the delay/shoot. What do you think?

To me, a pike-shoot and a tuck-shoot are just different styles of the same technique. Walker used to pike-shoot, but he doesn't any more. In fact, he's getting closer and closer to a continuous motion in his swing now.

I think tuck/shoot has been around for so long, it will be hard to shed that label for a new one. But between you and me, I'd be happy to refer to the tuck/shoot as a delay/shoot, because that's the crux of the issue for me - the DELAY and not the TUCK (or PIKE).

Kirk

[KirkB]

Petrov himself talks about forward/upward spring. But Launder emphasizes springing vertically in his book and I have run into other p/b advocates on line that also emphasize this.
If you spring off the ground in a forward /upward direction you will naturally also gain some vertical height as you do so.

The tricky part of explaining whether you're jumping JUST UP or UP and FORWARDS is that your intent and your resultant action is not one and the same. So you can INTEND to jump JUST UP, but because of your forwards momentum from your run, the end RESULT will be up AND forwards. For myself, I focused on jumping UP, knowing full well that I'd be going UP and FORWARDS. The semantics is tricky here, for that reason.

If you spring off the ground in a forward / upward direction you will naturally also gain some vertical height as you do so. It is my view that this is desirable because vertical take off movement naturally produces rotation in the pole's axis ...

Huh?

I think PVStudent explained this quite well, and to the right level of detail. You don't just want SOME vertical height, you want OPTIMAL vertical height. And an UP IMPULSE on takeoff is what gives you that.

Maybe DJ was emphasizing the ACTION of the UP IMPULSE as what rolls the pole ("Resultant Velocity"), but from a purely physics POV - as explained by PVStudent - even just the mere body posture with your toe just leaving the TO point is sufficient to roll the pole. Reaching up while on your toe is what increases the angle of the pole relative to ground level, which makes it easier to roll to vertical.

( if your springing action is correct there is no need to try to push the pole towards vertical with the arms during take off ).

I agree with your comment re the BOTTOM ARM here, but the TOP ARM?

You absolutely must STRETCH your top arm just as high as you can reach up, in order to increase the angle of the pole relative to ground level. Can you rephrase this? I can't believe that you think otherwise. I can't believe that you think having a correct springing action negates the need to stretch your top arm up as high as possible.

But if you generate too much vertical spring ( raise your c.m. too much ) as you leave the ground you will disapate (sp?) kinetic run energy ( the more you raise your c.m. the more energy you lose ). This is why you want to spring forward/upward not vertically.

I certainly agree that jumping STRAIGHT UP (like a high-jumper) would involve a braking action - fraught with energy leakage.

But now you're also touching on the question that I raised re Agapit and Altius having opposing views re pre-jump v. free takeoff. Clearly, you're advocating a free jump and NOT a pre-jump (as is Agapit), whereas Altius has advocated a pre-jump.

PVStudent, if you would be so kind, I would appreciate your reply to this - as you promised. You did clarify the free takeoff quite thoroughly in this thread, but you have yet to answer my question re the pre-jump confusion that I have (which is actually in this "What is your correct takeoff point?" thread: http://www.polevaultpower.com/forum/viewtopic.php?f=38&t=27151&p=185141. There, I have posed a serious, technical question that deserves a serious, technical answer. Thanks in advance.

Kirk

[PVstudent]

CoachEric and DJ you are both spot on.

David made the criticisms of The Petrov/Bubka Model. The more he reveals to us of his understanding of the fundamental tenet the Free Take-Off the more confused he appears to be about the objective Physical principles upon which it is based.

CoachEric succinctly put the free take-off into its context of the entire vault.

DJ your point re the resultant velocity is quite correct. I have to assume you are also giving due weight (no pun intended) to the rotational velocity effects on the vaulter about the axis at the wrists and the pole about the axis in the box.

Also the controlled velocity in the final 3 steps of the approach run is vital in making a successful linkage of the planting action in producing continuous motion throughout the plant and take-off.

The challenge for the vaulter is to conserve as much momentum generated by the run up as necessary to rotate the vaulter plus pole system about the pole tip in the box to enable the vaulter to do additional work throughout the pole bend and recoil phases to exploit the advantages offered by the implement at the grip placement on it.posting.php?mode=edit&f=38&p=186752#

Consider the vaulter in these two videos does he or does he not change his take-off and technical execution of the take-off towards that of a "Free Take-Off"?
His initial preferred take-off was to produce too much forwardly directed thrust even though the take-off foot placement was close to that required for a Free Take-Off.
Clearly in the first video the take-off is not free for there is a lot of pole resistance to the forward component of the thrust. After training in the second video the vaulter has changed the take-off to rectify this aspect of his take-off.
From my perspective this is dramatic change and I suggest results primarily from a higher vertical component to his take-off thrust effort.There are of course other improvements to be noted.
The take-off in the second video is much closer to being a "free take-off". My judgement may be quite wrong in this particular case if so point out the errors in that judgement.

http://youtu.be/9YK-7dZksCM
http://youtu.be/5c6LAvjAE2M

No David, the ball remains in your court. You made the critique therefore you need to explain why the physics and rationale underlying the Free Take-Off is mistaken which was and still is what my rebuttal to your position challenges you to do!

What so called Petrover's claim and what Vitali Petrov claims may or may not be the same at all.

Vitali Petrov's claims are on the public record and made to his peers around the globe for assessment and evaluation. His ideas as expressed through the performances of Sergei Bubka have shown remarkable resilience to the test of the arena and time.

In due course I will place on the public forum of PVP evidence of effective pre-jumps being used in competition. Scientific evidence of a pre-jump recorded and measured using force platforms and 6 degrees of freedom force transducers in the planting box for a 5.0m clearances over a bungy bar will also be made. In both these examples arguments can be sustained that neither are "ideal" in optimizing the vault by the vaulter but they do confirm that pre-jumps must also be included in the range of "Dynamically Functional Take-Offs".

Perhaps I am being obtuse and can't see through the fallaciousness of the "Free Take-Off!" Please somebody, anybody on this particular thread lift the veil from my eyes and show me that the conceptual reasonings that form the bases of the free take-off are wrong. Reveal that the emperor has all this time been parading around the planet naked!!! posting.php?mode=edit&f=38&p=186752#

[dj]

After all the definition of a free-take off is delaying bending the pole until the vaulter is off the ground ( which is STRONGLY impacted by the vaulter's take off point ). Correct me if I'm wrong.

Several studies show that taking off under, hence not using a free-take off, dissipates take-off velocity……………….

David.. both of these are correct.. butt I would say "as" the toe leaves the runway. There is nothing wrong with having a "goal" of a free takeoff. The issue is that it very, very rarely happens perfectly.

Even in the long jump where a jumper can hit 2" from the front edge of the takeoff board four of the six jumps, the results are rarely four 26' jumps and the difference is not the "technique', the takeoff angle, the height of the jump or the finish! It is always the "length of the last steps", posture and 99% of the time SPEED at the takeoff! Carol Lewis jumps 24', Carl Jumps 28'… the only difference in the scientific data is velocity over the last four steps and specifically "resultant velocity" at the takeoff!

Now to the "impulse'. Impulse at the takeoff, to me-and I have studied it intently and have worked with high level vaulters with it, without it, some NEVER wanted to "jump" and some all the wanted to do was jump. I didn't agree with any of them. It's a very "subtle" move in the pole vault. Not as pronounced as the long jump ie..where the takeoff toe is positioned maybe a little more in front of the COM.

It's a quick "tap', like a quick, straight legged "spring" with the foot under the COM and the lead knee, popping forward extremely fast, done just as the pole tip hits the back of the box and the top hand reaches full extension. I have demo-ed this on Youtube Dj impulse takeoff drill. What I'm encouraging is to "pop" off the takeoff from a full speed run, this is what I feel Bubka did on his best takeoffs..

This action isn't really a "Jump" it allows the mass to be moving "up" as the pole strikes the back of the box.. creating an accelerated transfer of momentum at the plant/takeoff.. a free-er takeoff if you will.


dj

PS. Kirk if the speed is carried through the takeoff and the plant proformed properly the "C" will happen if you don't fight it..