Trail Leg- Tuck or Petrov?

[vault3rb0y]

I think the petrov model will work for anyone who wants to jump high. No model is easy to learn, but the concepts are solid and studied, and they work. Joe Dial did things slightly differently, and it worked amazingly well. Tim could clarify, but possibly he couldn't hold higher and get on proportionally stiffer poles to still push 50"+ inches. So because he couldnt hold higher, maybe he was forced to find a way to push farther. That was by sacrificing angle at the take off for extreme swing speed. However even Tim has noted the difficulty in teaching the timing involved in their model (i believe in the oklahoma manifesto). The evidence is not solid and scientific for advantages of the tuck and shoot outwieghing the sacrifices you have to make to do so effectively, and although i anxiously wait for Tim's extremely bright and open mind to come up with more solid evidence, anyone who takes the tuck and shoot model in an attempt to vault 19'+ is taking a risk compared to the petrov model. The tuck and shoot is a model based on the limitations of certain athletes who generally can't jump off the ground with as much angle as the tall guys, and the petrov model is designed for tall, fast vaulters much like the stiff polers back in the day. Right now i feel that the petrov model will be the model to produce 20'+ vaulters, but if you are short and slow you will have a hard time vaulting 18'+ with it, and that the tuck and shoot allows ANYONE to push 50"+ and make ANYONE a 19' vaulter, but not much higher, and that if you can jump at a higher angle with a free take off, you are limiting your capabilities by using a tuck and shoot rather than the petrov model.

[superpipe]

As long as the athlete is hanging onto the pole, any energy created in the swing is going to be transferred to the pole. With a tuck it's just going to happen sooner. The only way speeding up the rotation of the swing can stop energy being transferred to the pole is if it is done before the swing has attained its highest velocity.

My bad. I shouldn't have said "stop transferring energy to the pole". You still do, but alot less than what you could have with a straight trail leg swing through out. The law of torque proves this. There's no way you could swing fast enough ( apply enough force ) in a tuck to create the same potential energy in the pole as a "slower" ( less force needed ) straight trail leg swing. Think about gears on a bike. In the lowest gear, you could not pedal fast enough to create the same speed as pedaling slow in the highest gear.

Also, when you tuck, you are now applying force to the pole at a lower point on the pole, meaning the pole is stiffer at that lower point and even more force would be needed in the tuck to equate to the lesser force applied with a straight trail leg. Compare the radius difference from a tuck swing vs. a straight trail leg swing to see where that radius would hit the pole. That's where the force is being applied to the pole.

Pretty confusing, but the simply fact is you have better leverage and can create more potential energy in the pole with a straight trail leg swing.

[powerplant42]

I think Vault3rb0y pretty much put this one to bed.

[VaultPurple]

petrov model is designed for tall, fast vaulters

i know im still a beginner but from my experiences, the longer i keep my trail leg and keep it straight all the way around like in the petrov model, the easier it is to get on big sticks. Im only 5'5 and would not consider my self to be all that fast.. but in my opinion petrov works just as good when you are short because it allows you to get on the bigger poles with more penitration.

[altius]

I am not even sure if 3po can put himself to bed.

[vault3rb0y]

petrov model is designed for tall, fast vaulters

i know im still a beginner but from my experiences, the longer i keep my trail leg and keep it straight all the way around like in the petrov model, the easier it is to get on big sticks. Im only 5'5 and would not consider my self to be all that fast.. but in my opinion petrov works just as good when you are short because it allows you to get on the bigger poles with more penitration.

You didn't understand what i was trying to say

When i said that the petrov is proven to work, that is exactly what i meant. There is no doubt you can jump 18'+ with BOTH models. Its getting beyond that point that you need to decide what model to go with, but you need to decide well before you get to that point. But with the instability of the tuck and shoot's model, and the difficulty in learning the timing, i think all people are better off learning things from the petrov (or 6.40) model, and making variations in technique once you level off with your performances. If you jump 18' but dont get any better for 2 years, not just in PR but in technique perfection and pole progression, you might experiment with more aspects from the tuck and shoot model. But until then, whether you are 5'0 and run 10m/s or 6'0 and run 7m/s, it is better to follow what is proven to work.


And this topic will never be put to bed, as long as new information is presented and new ideas come up. This brainstorming is crucial for the progression of the vault, but for the relatively new vaulters such as myself, we should be focusing on understanding why and how the petrov and 6.40 model work before figuring out tweaks like a tuck and shoot that might help someone more physically shaped to do so.
Its like trying to put a turbo in a car before you know how to change the oil, you are just going to mess something up.

[Tim McMichael]

I think the petrov model will work for anyone who wants to jump high. No model is easy to learn, but the concepts are solid and studied, and they work. Joe Dial did things slightly differently, and it worked amazingly well. Tim could clarify, but possibly he couldn't hold higher and get on proportionally stiffer poles to still push 50"+ inches. So because he couldnt hold higher, maybe he was forced to find a way to push farther. That was by sacrificing angle at the take off for extreme swing speed. However even Tim has noted the difficulty in teaching the timing involved in their model (i believe in the oklahoma manifesto). The evidence is not solid and scientific for advantages of the tuck and shoot outwieghing the sacrifices you have to make to do so effectively, and although i anxiously wait for Tim's extremely bright and open mind to come up with more solid evidence, anyone who takes the tuck and shoot model in an attempt to vault 19'+ is taking a risk compared to the petrov model. The tuck and shoot is a model based on the limitations of certain athletes who generally can't jump off the ground with as much angle as the tall guys, and the petrov model is designed for tall, fast vaulters much like the stiff polers back in the day. Right now i feel that the petrov model will be the model to produce 20'+ vaulters, but if you are short and slow you will have a hard time vaulting 18'+ with it, and that the tuck and shoot allows ANYONE to push 50"+ and make ANYONE a 19' vaulter, but not much higher, and that if you can jump at a higher angle with a free take off, you are limiting your capabilities by using a tuck and shoot rather than the petrov model.

Great post.

[volteur]

What is Petrov really saying about the leg during the early rockback? Is he saying keep the leg straight? Is he saying a slight bend is a bad thing? Is he saying tap like during a kip in gymnastics? What is the essential element to the rockback and has he ever revealed it?

cheers

Volteur

[altius]

"What is the essential element to the rockback and has he ever revealed it?"

Petrov outlined his views on the rock back - a term he does not really like -in his original presentation in Birmingham in 1985. Surprised you did not know that old son. Guess where you will find that paper reprinted as an Appendix??

[vault3rb0y]

haha.
nice.
I must admit i dont have that book and it IS possible to learn a lot without it, really everything without it, but man am i looking forward to reading it this summer. It seems to make things a lot easier.

[exvaulter]

After Bubka quit vaulting we can see a clear lack of development in results, and also in vaulting technique. No one has ever vaulted close to the perfection of Bubka.
The "tuck and shoot method" seems to dominate among vaulters and is sadly enough the mos used way of performing the body swing. This method has a drawback that, to my knowledge has not been in focus. Here is my point of view why "tuck and shoot" can never work to beat the WR.

1) When you tuck your legs in sharply then your center of gravity is relatively low (relative to your grip on the pole).
2) Then, when you straighten up your body into a nearly vertical position the center of center of gravity suddenly rises, maybe around i foot.
3) When the CoG rises the pole will recoil as a reaction.
4) And if the pole recoils at that moment (too early), then you will get no help from it to lift you over the bar.

If you succeed to get into a truly vertical position (like Bubka) while the pole is still bent, then you have the extra power from the pole when you need it, and you will be able to get the tremendous lift over the bar that Bubka had.

But if you, by tucking in and then straighten ut have let the pole recoil before you turn and then you MAY may reach a good height, but then you will fall down on the bar because you lack the momentum from the pole.

This way of explaining why the tuck and shoot method is a poor one I think has not been pointed out. Clearly a lot of coaches have remarked that the sharp tucking will cause your pole to recoil, but I guess they don't explain why.

[KirkB]

Exvaulter, I’m sorry, but that’s not it. Your description of the tuck defies a law of physics.

I agree that the tuck and shoot is inferior, but not for the reason that you’ve stated.

The most correct part of what you said is:

But if you, by tucking in and then straighten out have let the pole recoil before you turn and then you MAY may reach a good height, but then you will fall down on the bar because you lack the momentum from the pole.

That part is correct – you imply that you have [improperly] let the pole get ahead of you. So I know you understand the physics of it. You just haven’t explained it correctly.

Let’s break this down …

1) When you tuck your legs in sharply then your centre of gravity is relatively low (relative to your grip on the pole).

Relative to your hand grips – true.

2) Then, when you straighten up your body into a nearly vertical position the center of gravity suddenly rises, maybe around 1 foot.

OK, as you say, relative to your hand grips (not relative to the box, as that will depend on the coil/recoil of the pole AS WELL AS to the position of your CoG relative to your hand grips). So far, so good.

3) When the CoG rises the pole will recoil as a reaction.

Not true! Every action has an equal and opposite reaction. So if your CoG is going UP, then there’s a DOWNWARDS force on the pole. In reaction to ONLY this force, the pole doesn’t tend to RECOIL – it tends to COIL - the opposite of what you’re stipulating!

I say “tends to” in order to distinguish the direction of the force from what actually happens. What actually happens will depend on the relative flex of the pole to the amount of force exerted in the extension, as well as the state of coil/recoil that the pole is already. You have to sum the forces in each direction to determine the NET force. The net force is what will cause the pole to actually coil more or recoil more.

If you consider where the pole is in its coil/recoil sequence when the vaulter extends (i.e. shoots out of his tuck), you are likely incorrect in saying WHY the pole will recoil. As you extend, it will recoil, but not (as you say) because of the force of the rise in the CoG, but because of the return of the pole’s potential energy back to kinetic energy – energy that was injected during the bottom half of the vault.

4) And if the pole recoils at that moment (too early), then you will get no help from it to lift you over the bar.

This part is true, if you replace “get no help” with “not get as much help”.

Tuck/shooters typically let the pole get ahead of them during the bottom half of their vault. That’s the reason they tuck – to catch up to the pole’s imminent recoil. I say “imminent” because they start tucking during the last part of the coil phase of the pole (near where the CoG passes the chord), so that by the time they’re finished the tuck, they’re ready to “shoot” in time with the recoil. But typically, they’re either tucking too early, or shooting too late (for optimal energy conservation).

If they’re shooting early enough (i.e. exactly in unison with the recoil of the pole), then they would have had to tuck during the coil of the pole – at a time when they could have driven more energy into the pole (with a long trail leg, right through the whip and then some). As soon as they tuck, they’re not loading the pole (optimally) anymore.

IMHO, there’s also leakage involved in a tuck. In the continuous chain method (a part of the Petrov model), the entire body is somewhat rigid – not relaxed. That minimizes leakage. Not so with a tuck.

Furthermore, the “shoot” of a tuck/shooter is usually too quick. If it’s not done in full unison with the entire recoil of the pole, then it’s less efficient. This deficiency is much more pronounced with young vaulters than with elilte vaulters, but even with the very best tuck/shooters, it's not a single continuous and harmonious action - free of leakage.

Having said that, there is one advantage that I believe tuck/shooters have over followers of the Petrov model (and in particular, their continuous, harmonious swing from the Whip to the Extend). The tuck/shooters’ advantage is that they can time their “steer” much better. All they need to do is vary the amount of time that they pause in the tuck. Then they shoot when they feel the pole has rolled sufficiently to vertical. Some can also see the bar then, and aim their shoot accordingly.

Petrov model vaulters (myself included) can’t do this as easily. Since we’re doing a “continuous chain”, we have to keep that motion going. There’s no point in the flow at which you can pause if you’re too far behind the pole. Conversely, there’s no point in the flow in which you can speed things up (i.e. there’s no opposite to “pause”) if you’re ahead of the pole. By definition, a “continuous chain” is just that – there’s not as much opportunity to speed it up or slow it down. Thus, you can’t time the “steer” as easily.

As always, my assertions about my technique (a variant of the Petrov model) are based on personal first-hand experience, but my theories on tuck/shooters aren’t – I’ve never tried that technique. They’re based only on observation and physics.

Kirk