Pole vault research paper: influence of pole plant timing

[agapit]

I guess my point regarding the study conclusion was that they were asking the wrong question from the beginning. Their question was whether the plan method and timing of plant/jump affects total energy after the takeoff, and my point is, if you do not think pole vault at all and just think mechanics, that there is no reason why the energy at the moment of leaving the ground would be different with any plant method. What would be different is the position of the vaulter for the following actions and the trajectory of COM and the post-takeoff position has huge implications on the rest of the event.

In a sense the researchers were measuring who gets first to a Berlin railway station to go to Frankfurt and they were assuming that whoever gets there first will get first to Frankfurt, however they completely disregarded that one train maybe express bullet train and the other steam powered sightseeing locomotive. Excuse my metaphor.

So based on the experiment conclusion that the plant method has no influence on the level of energy after the takeoff, if I understand it correctly, some maybe misled into a view that the plant method has no influence on the whole event and that is the wrong conclusion. The athlete’s position and the direction of COM following a particular version of the plant/jump complex has everything to do with the final result! That final position and COM direction and not energy considerations are main objectives of the free takeoff, in my opinion.

[altius]

Yes indeed - and do you want to go to Frankfurt am Main or Frankfurt an der Oder?

[agapit]

Yes indeed - and do you want to go to Frankfurt am Main or Frankfurt an der Oder?

i am main myself, but i see you point, even more veriety in that order:)

[grandevaulter]

If you want variety and a langsam zug ( slow train). Take the hand car line from Lengenfeld to Dinglestadt just east of the old fence back in the Hiemat. Probably not the right answer to the wrong question either.

[coachjvinson]

The concept stated in your conclusion in this post and others really sums it up: yourself and several others on the forum have impressed this upon my own thoughts and methods...

However, it is not just preservation of energy that is at stake at the takeoff, no pun intended! The potential height of the jump depends on the total energy generated and preserved during the whole event not just run-up/takeoff. And if one considers the whole jump then timing of the plant and takeoff as well as the direction of the takeoff significantly influence ability of the athlete to further generate energy input in the system. See my discussion about passive and active phases. Also the most important parameter in the achieving higher clearance is the vertical speed component of the center of gravity or COM and having the most streamlined COM trajectory without significant decelerations/accelerations is essential! And however great Billy Olson’s achievement and potential was, we estimate that Bubka’s was about a foot higher!!!

V

[coachjvinson]

I also think it is worth noting that while bio mechanists have usually managed to explain (retrospectively) why things work in track and field, they have never developed new and effective solutions to the problems athletes face as they strive for excellence.

Kind of affect vs effect: what I do like about this study is that it stands as an example of how to measure, how not to measure, what to measure and what values to place on the measurements in the overall equation. The best thing that may result from this study is assisting the next research group in planning their experimental design.
V

[agapit]

I also think it is worth noting that while bio mechanists have usually managed to explain (retrospectively) why things work in track and field, they have never developed new and effective solutions to the problems athletes face as they strive for excellence.

Kind of affect vs effect: what I do like about this study is that it stands as an example of how to measure, how not to measure, what to measure and what values to place on the measurements in the overall equation. The best thing that may result from this study is assisting the next research group in planning their experimental design.
V

It was a helpful study in term of crystalizing understanding of why the plant is important. And it is not, as the study showed and one could theorize, about generating more or less energy by varying timing and style of the plant, but rather about the position of the body and COM trajectory after the takeoff, in my opinion.

So the study measuring post takeoff energy input, using tenso platforms as well as high speed camera may reveal interesting information about effect of the plant and the timing of the plant on distribution of energy and addition of energy into the system during the off the ground phase.

I am aware of a German study in Seoul Olympics where, if I remember correctly, only two athletes added significant amount of energy in the off the ground phase - Bubka and Egorov and both have drastically different plant and action on the pole.

What I would look for, are patterns in resistance of tenso platform where “jaggedness”, I theorize, would indicate less efficient work on the pole and also higher energy input through the off the ground phase would indicate a more preferred situation.

Now connecting these elements to “free takeoff” vs. resisting pole on the ground could reveal more about desired plant style. However, I am not sufficiently familiar with that equipment to estimate feasibility of such measurement. I remember from the past looking at the resistance graphs from tenso measurements that they were variable in shape, but at the time we could not make out of what that means and if it is important or not and why.

[agapit]

Just bough this article for $31.50. Although it confirms items that I have mentioned in earlier posts, the major point of the study is that they used “Jagodins” (takeoff without inversion), I know the old man would be thrilled that there is an exercise named after him and recognized worldwide. So the selection of this test exercise, from the beginning, shows that researchers were narrowly interested in the only effect of the plant and its timing on the energy after the takeoff.

As I mentioned earlier, if one does not think pole vault, but general mechanics, it is difficult to imagine that under normal circumstances the energy would be significantly different regardless of the type and the timing of the plant. There are just no external forces involved that could affect the outcome. Furthermore, with the fiberglass pole, acting as a shock absorber/energy accumulator, even the effect of the pole angle to the ground is less important for the energy losses in the whole system, as compared to rigid pole, where the lower pole angles generates greater resistance forces and losses and no absorption whatsoever, ouch shoulders.

And strangely enough the article mentions that early takeoff, as I pointed out, could be less energy efficient due to energy losses of the skeletal muscular system.
I have written in one of the way earlier (2-3 years ago) articles on this website about the optimal takeoff angle in pole vault and based on similar to the study considerations, I have theorized that the optimal takeoff angle would be somewhat lower than in a long jump and would be determined by the presence of passive phases in the off the ground phase. Understanding that lower takeoff angle would inevitably generate longer passive phases and not only that but redistribute energy from raising of COM to the pole bend and produce “jagged” trajectory of COM and that is why it is important to have a “free takeoff” that ends with the proper position for further actions on the pole.

So, in practical application the athlete’s ability to jump off the ground and the mix of passive phases would determine the timing and even position of the plan/jump for that moment’s optimal performance. However, long term view “free takeoff” method is preferred method because it allows for development of that jumping ability and the “resistance on the ground” method does not. Therefore, the first has a potential to generate a positive feedback loop for further physical development and the second does not. Obviously the study in question did not take in consideration these “positive feedback loops” either, as it is a really long term (multiyear) development strategy and could not be assessed in a short term study. Now the kick is, that most who use “free takeoff” do not take advantage of it in that way.

So, I probably will buy a few more articles from that magazine (Journal of Biomechanics).

[altius]

"Now the kick is, that most who use “free takeoff” do not take advantage of it in that way."

I have my own ideas on that topic but it might be a bit more useful if you explained - again - why this is so and what can be done about it. Probably better use of your time than reading yet more articles on biomechanics. Never forget that most of the folk producing that stuff are only interested in getting a journal article accepted - not in moving the coaching of the pole vault forward.

Any news on next July???

[agapit]

"Now the kick is, that most who use “free takeoff” do not take advantage of it in that way."

I have my own ideas on that topic but it might be a bit more useful if you explained - again - why this is so and what can be done about it. Probably better use of your time than reading yet more articles on biomechanics. Never forget that most of the folk producing that stuff are only interested in getting a journal article accepted - not in moving the coaching of the pole vault forward.

Any news on next July???

I'm developing a subscription website where I will systematize all I have learned in 35 years (scary to think), since I have first touch a bamboo pole and landed in sawdust. I plan the site to launch by mid-January.

[coachjvinson]

Looking forward in anticipation....

[agapit]

Looking forward in anticipation....

don't be sarcastic, I'll do my best