Swing Efficiency Comparison: Bubka, Tradenkov, Lavillenie

[PVstudent]

My own cut to the chase calculations...

KE = 1/2 m v squared

Bubka = 1/2 x 80kg x 9.94 m/s x 9.94m/s = 3952j
Tradenkov = 1/2 x 78kg x 9.47m/s x 9.47m/s = 3498j

Quite extraordinary ! You are repeating the same error, namely using average horizontal velocity measurements, which are the velocities the vaulters had at approximately a horizontal distance out from the rear wall of the planting box of 7.5m . Even with 6.5m long vaulting pole and a massive pre-jump neither vaulter was or could be capable of such a feat. Your math is correct but your input data is just wrong.

Let me point you further, no sophistry, just trying to be helpful by encouraging you to read these studies!

Influence of the pole in pole vault study by the biomechanists based in Cologne.jpg (63 KiB) Viewed 6825 times

Influence of the pole in pole vault study by the biomechanists based in Cologne 2.jpg (75.13 KiB) Viewed 6825 times

Below I refer you to the only study to date, that I am aware of ,that considers the pole dynamics having, so far as I can determine, each individual pole calibrated as to their load bearing, deflection and recoil characteristics and measuring actual pole vaulter - pole interactions using a combination of force transducers in the planting box, strain measuring transducers in a test pole, combined with synchronised video analysis under controlled experimental measurement not competition conditions. Note the engineers / scientists are from the University of Bordeaux!

Morlier and Mesnard study from the Bordeaux University Group.jpg (50.81 KiB) Viewed 6825 times

Enjoy!

If you put these reference details into Google Scholar you can access the full material.

Mathematical model of the takeoff phase in the pole vault
NP Linthorne - Journal of Applied Biomechanics, 1994

Energy loss in the pole vault take‐off and the advantage of the flexible pole
NP Linthorne - Sports Engineering, 2000

PDF] 4 Energy transformations in the pole vault
NP Linthorne - people.brunel.ac.uk

[PVstudent]

Trandenkov v Lavillenie and free take-off.jpg (101.64 KiB) Viewed 6825 times

Readers are invited to review the material on the videos referred to and snapshots above and consider their evaluations vis -a -vis qualitative estimation of relative efficiency of take-offs and of course approximation to the foundational premises of the Petrov-Bubka Technical Model of Pole vaulting.

I note with great disappointment that PVdaddy is using the royal "we" to link himself to Willriefer's efforts and continuing to muddy the already very murky waters.

[PVDaddy]

PVStudent; I note with great disappointment that PVdaddy is using the royal "we" to link himself to Willriefer's efforts and continuing to muddy the already very murky waters.

That is complete Bunk! Will is the one who gets great credit for started my thinking about the gravity vector of the vaulter and its relationship to the pole and swing being the astute thinker he is! The idea and way of approaching how to calculate swing efficiency was mine, as is my detailed description, on what is now numerous post, on how and why I believe Lavellenie achives it.

[PVDaddy]

That being said, I would also add Will has been assisting me with some physics and I will glady point out he is on a whole different level then me and I suspect by your post, you as well. What I do think we have in common (I can't speak and wont speak for Will) is that we both systematically stay focused on the major most important elements of discussion and do not try to distract from it by throwing out the Baby with the bath water based on minor distractions and sophistication's as yourself.

Of course being co-author and Biomechanist of this book you have to sell makes this ALL very dangerous territory for you!

[willrieffer]

My own cut to the chase calculations...

KE = 1/2 m v squared

Bubka = 1/2 x 80kg x 9.94 m/s x 9.94m/s = 3952j
Tradenkov = 1/2 x 78kg x 9.47m/s x 9.47m/s = 3498j

Quite extraordinary ! You are repeating the same error, namely using average horizontal velocity measurements, which are the velocities the vaulters had at approximately a horizontal distance out from the rear wall of the planting box of 7.5m . Even with 6.5m long vaulting pole and a massive pre-jump neither vaulter was or could be capable of such a feat. Your math is correct but your input data is just wrong.

Let me point you further, no sophistry, just trying to be helpful by encouraging you to read these studies!

Influence of the pole in pole vault study by the biomechanists based in Cologne.jpg

Influence of the pole in pole vault study by the biomechanists based in Cologne 2.jpg

Below I refer you to the only study to date, that I am aware of ,that considers the pole dynamics having, so far as I can determine, each individual pole calibrated as to their load bearing, deflection and recoil characteristics and measuring actual pole vaulter - pole interactions using a combination of force transducers in the planting box, strain measuring transducers in a test pole, combined with synchronised video analysis under controlled experimental measurement not competition conditions. Note the engineers / scientists are from the University of Bordeaux!

Morlier and Mesnard study from the Bordeaux University Group.jpg

Enjoy!

If you put these reference details into Google Scholar you can access the full material.

Mathematical model of the takeoff phase in the pole vault
NP Linthorne - Journal of Applied Biomechanics, 1994

Energy loss in the pole vault take‐off and the advantage of the flexible pole
NP Linthorne - Sports Engineering, 2000

PDF] 4 Energy transformations in the pole vault
NP Linthorne - people.brunel.ac.uk

As to the second part first. I will try to look at these as they are of interest. It will likely take some time. It's physics after all. And sometimes I have things to do like a problematic automobile among other things...

As to the first part. Sometimes the IAAF data is good for you, and other times its not? Like I said, I had total transparency in my data AND I made caveat about its nature. OR, if you don't like the PVP 6m table velocity column and you think its misleading in some way, why not try and get it changed? I mean for clarity, I can certainly believe that Bubka's v mark is a one time high point measurement. Is Tradenkov's averaged? Max v? I don't know. But I call into question this very fact in analysis to give readers a sense of the reliability of the analysis. One of the most important parts of the IAAF data is that it shows well the relationship of height achieved and meet rank order are relative to this measurement which you now here call into question. We know why this is, because of the dominance of velocity squared in the KE equation. Or, its the easiest to get and simplest to understand point predictor of vault height in similarly accomplished vaulters. And again the IAAF video made particular effort to stress Bubka's speed and measured acceleration at that point. In that I framed what was being done, fully, you've left an incomplete critique again outside of making your own full clarifications. That is, I would advise you present other better data in frame and for clarity. Or, it is I find I have a good sense of Bubka's speed between the IAAF data, general acknowledgement of his speed, and the PVP 6m club chart. For Tradenkov, not so much. IF you've got it or can get it and show it to me here, I'll be happy to recalculate. I will note that max speed has merit again because of the nature of the KE equation, which is that we should reasonably assume that max height, or max PE, is paired with attempts at or near max v. I'm willing to give Bubka some leeway on this, but again the IAAF data places him with several accelerating attempts approaching 9.9 m/s.

It also might make one pause as Vigneron came in second and was slowing through the trap. Oh, those pesky French!

WIll

[willrieffer]

Trandenkov v Lavillenie and free take-off.jpg

Readers are invited to review the material on the videos referred to and snapshots above and consider their evaluations vis -a -vis qualitative estimation of relative efficiency of take-offs and of course approximation to the foundational premises of the Petrov-Bubka Technical Model of Pole vaulting.

I note with great disappointment that PVdaddy is using the royal "we" to link himself to Willriefer's efforts and continuing to muddy the already very murky waters.

Thanks so much for providing a video of Tradenkov that I have been somewhat searching for without success.

He enters with quite a bit of bend and left arm contention and where he's quick and active to repress. Early posture remains immaculate even under pole bend. Fantastic work "back" in the early mid swing stage. And tuck to get out in time.

I had predicted his actual efforts would approach Lavillenie. Visa versa is not a problem either.

Thanks again.

As to the Lavillenie vids. Wow, is he hanging on the pole. While placement and posture are excellent, I see little to no effort, "to win a high jump contest', with a nod to Joe Dial. It's hang, hang, hang, and then a "roll" up to invert.

Again, good stuff. Thanks.
Will

[willrieffer]

PVStudent; I note with great disappointment that PVdaddy is using the royal "we" to link himself to Willriefer's efforts and continuing to muddy the already very murky waters.

That is complete Bunk! Will is the one who gets great credit for started my thinking about the gravity vector of the vaulter and its relationship to the pole and swing being the astute thinker he is! The idea and way of approaching how to calculate swing efficiency was mine, as is my detailed description, on what is now numerous post, on how and why I believe Lavellenie achives it.

Look,

For any complex problem of this nature you want a team. Doesn't have to be all smiley faces and back patting and in fact some friction is probably to be desired. You just need other minds looking at things in different ways and checking your work because its so complex and complicated. I worked on a team in High Tc Superconductivity. Team. That's why when I continually forget to think about starting CoM (and why I have a continual blind spot there I don't know) I take on the corrections and move on. Canag did me a great favor and PVStudent keeps me on my toes as well. I just have an idea and want to get to the truth of it as best I can, we can, to see if has any validity. And I'm a continually getting older man with diabetes and other health issues. Sometimes if my sugar gets off or if other effects creep up I make mistakes, I can't think like I used to, and I make mistakes. But heck, I made them when I was a student. Its just this again is too hard and complicated to crack in moments and without mistakes.

PVDaddy, at least recently has done some good work in at least asking pertinent questions about what is going on and crystallizing his thoughts. Likewise, we have not agreed on every aspect of our analysis and thinking. So it goes and I wouldn't have it any other way.

History. Some of you already have it, and it appears I'm building it. So it goes...

Will

[willrieffer]

Lavillenie front foot lower.jpg (33.62 KiB) Viewed 6791 times

https://www.youtube.com/watch?v=RtZH3Q19w4I

IN the video you can get a good slomo look at the action he uses with his feet. Still is from around the 3:20 mark. The front leg almost has a "bicycle" action. He drives the knee but without any lapse starts rolling it over until the point that it appears it actually drops lower than the back extended take off leg. Very interesting. Front leg drives and then immediately starts lowering CoG relation while the trail works back. All rather interesting and unique I would say.

He seems somewhat more actively "jumpy" in these than some of the other vids, particularly the last referenced training one.

Will

[KirkB]

Will, I'm enjoying your non-confrontational style of working towards a common end goal here. Now that I know you work (or did work) on a high-tech TEAM (there is no 'I' in 'team'), I understand your teamwork better, as I too work with software development teams. Teamwork can be fun too!

... The front leg almost has a "bicycle" action. He drives the knee but without any lapse starts rolling it over until the point that it appears it actually drops lower than the back extended take off leg. Very interesting. Front leg drives and then immediately starts lowering CoG relation while the trail works back. All rather interesting and unique I would say. ...

Would you agree that it's not so much that he 'drops' the lead knee, but that the trail leg catches up to it?

Maybe this creates an illusion that I saw a week ago, where I thought he was pausing? I got the impression that he was just hanging on the pole, yet there is the counter-argument (equally as valid, if not more so) that he's adhering to the Continuous Chain of Motion Theory - always moving forwards/upwards? I'm seeing it both ways now.

Kirk

[willrieffer]

Will, I'm enjoying your non-confrontational style of working towards a common end goal here. Now that I know you work (or did work) on a high-tech TEAM (there is no 'I' in 'team'), I understand your teamwork better, as I too work with software development teams. Teamwork can be fun too!

... The front leg almost has a "bicycle" action. He drives the knee but without any lapse starts rolling it over until the point that it appears it actually drops lower than the back extended take off leg. Very interesting. Front leg drives and then immediately starts lowering CoG relation while the trail works back. All rather interesting and unique I would say. ...

Would you agree that it's not so much that he 'drops' the lead knee, but that the trail leg catches up to it?

Maybe this creates an illusion that I saw a week ago, where I thought he was pausing? I got the impression that he was just hanging on the pole, yet there is the counter-argument (equally as valid, if not more so) that he's adhering to the Continuous Chain of Motion Theory - always moving forwards/upwards? I'm seeing it both ways now.

Kirk

I'm watching it again and its subtly marvelous.

The work angle of the right leg knee. Well, you can keep working it forward and up, and in which case its going to pull the whole system forward in the hips/hip separation. Plus such action wants to straighten or roll the torso mid section. His action is opposite and while he brakes the top through the front arm and shoulder he rotates the feet and by them the legs and hips over forwards. So you get this very long elongated stretch arch where he almost transposes the legs. This is where his front leg actually is the straighter leg of the long axis and his trail leg is back keeping the CoM back. Then as you say the trail catches up, and he "normalizes" for a bit right before he does what I call the "roll up" to inversion. Where most swing up, his is more like rolling up to invert on a high bar.

I watched a bunch and focused on the top arm relation early where I think he fights harden than most to keep from going forward and opening the posterior angle. You can faintly see a force wave through the top and down the torso. Where most just flow into the C, he at first appears to work like heck to block its onset but then seems to put a little bit of arch back into his length before normalizing. So where most arch into the C and straighten, he almost appears to work to stay straight and then arches a bit while keeping the trail back longer. It has the look a bit like a pre move set up action like a gymnast on a bar might use.

There's another good slomo at 2:42 of this one showing same action...

https://www.youtube.com/watch?v=E1YOs_cum_8

Will

[PVDaddy]

Yes finally the slo-mo of Lavy's Vault! Thanks Will. I have been eagerly waiting for one. So glad someone captured this and posted it.

I see very little knee drive through his take off going into penetration. I had posted prior that I felt his knee drive was not any more then Just the continuation of his running stride. Now after being able to examine it much better in slow-mo I don't feel it is even that much! Note the upward stride height (Approx. 90 degrees) of his knees during run-up. I don't believe his range of motion of his drive knee goes that far into his drive. I believe he relaxes his drive leg muscles short of that while elevating his take of leg back for counter balance and like Will points out goes into a relaxed bicycle type motion with the relaxed drive leg coming down while the take-off leg is extended up to the point the drive foot dangle below the take off foot. To me it appears he lets it hang loose momentarily until the swing leg catches up with it and then he goes into his quasi double leg swing into a tuck. Just look how far below the pole Lavellenie is! I believe the take off is flatter, with the effort off the take-off foot and leg driving more to the horizontal then Bubka's.
Is there any question he is making every effort to keep his COG as low as possible into take-off and throughout the swing? Is there any doubt by anyone that he has a very low swing path during his downswing? Will do you feel that this lowering and hanging of the drive knee through this bicycling motion while keeping below the pole keeps Lavy's COG lower as his body moves forward and is an excellent example of what you mean by braking his low COG swing into the pole?

[PVstudent]

Below another Petrov Method trained vaulter at take-off.

Gibilisco a Petrov Vaulter.jpg (101.8 KiB) Viewed 6735 times

Below is a Renaud Lavillenie Take-off a non Petrov Method trained vaulter and current Indoor World Record Holder 6.16m jump. Note this is not his record jump take-off.

Renaud Lavillenie 6.01m take-off 1 2013.jpg (98.11 KiB) Viewed 6735 times

Renaud Lavillenie 6.01m take-off 2 2013.jpg (54.4 KiB) Viewed 6735 times

Both vaulters I think would be thought of as "tuck and shooters" if a coach was asked to classify them on their respective pole support to pole release dynamics!

Compare them carefully at their take-off. The most striking feature, to me, given both vaulter's are slightly "under " according to their take-off foot placement ,is the similarity in their form and dynamics of the plant and take-off

Again, if the identity of these two vaulters were unknown to you and the video record stopped at the final frame shown in the sequence, would your assessment be neither, one of them only, or both could be considered Petrov Method trained?
(I am of course assuming the reader is fully cognisant of the conceptual thinking underlying the "Free Take-Off").

Now, without any further evidence which of the two ,based on the images presented above and ignoring your pre-knowledge(very difficult challenge for everyone), would you predict will show the most lead leg lowering (voluntary or involuntary lowering) during the pole chord shortening and penetration part of the first phase of pole support? In answering this question for yourself identify your reasons for the conclusion you arrive at. In my following post there will be some images of another vaulter to help you in your deliberations.