GRV: Lavillenie - From Stall Swing to World Record

[PVstudent]

He doesn't push, he PRESSES UP with the inside pad of his left hand!

Charlie thank you for your emphatic response that Renaud "presses up".

Can you elaborate and clarify why or if you think Renaud intentionally presses upward.

I can accept that this is what a vaulter reports as occurring and that the external observer believes they see.

Can the pressure the vaulter experiences on the inside pad of the lower grip hand be due to the pole reaction to the centripetal force created by the vaulter's powerful leg swing?

It is my understanding that Renaud is swinging from two pivot points formed by the grips on the pole and not just the top grip alone.

I am interested to hear your views on the issue.

[charlie]

I think your pole reaction is correct and a combination of both! cause and effect!!!

[canag]

It might not be relevant to the present discussion because it happens a bit later in the vault, but there is a point that has always puzzled me: in the second phase of the jump (when the left leg passes vertical axis) his left hand only grabs the pole with the fingers' end, not the palm. So at this stage, I think he's more trying to be as far from the pole as possible with his left hand than to bend the pole by pushing it up.
This observation does not come from a scientific analysis but just by watching Renaud's videos of a training camp just before the WR http://youtu.be/YzUF9Kw71LQ (particularly visible around 1'40, green tights).

The only image I could find showing this point is this one, even later in the swing: http://tinyurl.com/m2eaonn

[grandevaulter]

willrieffer wrote:
It creates a complex curve for the CoM to follow and analyze and to do this discretely, at each step in time, which is what calculus does, makes it that much harder. You guys, most of you, have no idea how hard this is. I keep trying to show it and make it as simple as possible just to sort of get started. And yet its met with open ignorance by some and ignorant resistance by others...

Or you could just read and analyze illustrations on page 43 and 44 of BTB2.

Grandevaulter wrote: What was that you are trying to map ? Should be a snap for a scientist.

grandevaulter wrote:
As I have stated in the past, Altius was intelligent and knowledgeable. He published a book on kinetics that was used as text for Ohio State University. He was a math and PE major at Loughsburough University and received his masters at Western Kentucky. He chose not to dialog with you for the same reason he would not ask what the "price of snails in China" is. You didn't know Altius or the PB technical model. You are not qualified.


Willriefer wrote: To be honest, I don't doubt that. But here's the problem with both you and him. He choose not to engage me on the subject in terms of math and physics. That's his fault not mine. So while he may not have been an idiot about math and science, he sure chose to look like one to me. His choice, not mine.

Good thing you didn't ask him to waste his time with the "gravity vector".

Thank you Canag and PVstudent for clearing this up.

[willrieffer]

Wow. Its the same old stuff. More smoke and mirrors that dances around the subject without ever once engaging it head on.

So we get RL's CoM path. What hasn't been done is a vector calculus on the swing angle to gravity vector. Still hasn't been done, which shows the variation of the gravity force on compression rate. I don't think anyone here can even begin to grasp the level of mathematics it would take to do this...

Again, I'm not interested in the push force of the lower arm as a force of note bending the pole. That is not what I'm talking about at all. What I know must be fact is that when the arm is extended, it effects the swing angle in time and thus the relation to gravity and its effect on the pole. IT has to be by simple geometry... This is in the same way two different length pendulums will naturally swing at different frequencies. I don't have to prove this. It has been proven. It is basic science or geometry.

When Einstein proposed the Theory of Relativity, it was a thought experiment followed by a mathematical proof. What followed was a mission to collect observable evidence. Arthur Eddington had to travel to the west coast of Africa to take astronomical photos of a full eclipse to prove the theory. It did not work initially from observation, but again from math and physics ideas which proposed an observational experiment. Which is what I am doing. Again, people here do not know nearly as much about science nor philosophy of science to be critics...

I have proposed that RL does things, which I have described, which alter his swing rate, which in turn alter his swing relation to the field of gravity and then effect on the pole. This alters his CoM path. Simply showing his CoM path, and then sort of waving your hands about what it means, means nothing to me. No one has even taken on my ideas let alone disproved them... "But is that scientific fact or just opinion?"

I mean I show well known sources for basic physics ideas and concepts that have been proven experimentally and mathematically and people want to disagree with those ideas. And I'm the one that's off. Whatever.

Season is on. I have kids to coach and less time to fritter away on wasting time here...

Will

[grandevaulter]

So we get RL's CoM path. What hasn't been done is a vector calculus on the swing angle to gravity vector. Still hasn't been done, which shows the variation of the gravity force on compression rate. I don't think anyone here can even begin to grasp the level of mathematics it would take to do this...

It seems to lead us back to the boring old mass, velocity and take off angle and the amount of energy put in, stored and produced by the human with their own muscles. Not a stick man or drawing of a stick and a ball or Wiki cut and pastes.

Gravity seems to be negligible. But your attempt to discredit and insult are too. Read pages 43 and 44 of "From Beginner to Bubka and Isenbayeva too". The illustrator maps three types energy throughout with the use of a graph.

[willrieffer]

So we get RL's CoM path. What hasn't been done is a vector calculus on the swing angle to gravity vector. Still hasn't been done, which shows the variation of the gravity force on compression rate. I don't think anyone here can even begin to grasp the level of mathematics it would take to do this...

It seems to lead us back to the boring old mass, velocity and take off angle and the amount of energy put in, stored and produced by the human with their own muscles. Not a stick man or drawing of a stick and a ball or Wiki cut and pastes.

Gravity seems to be negligible. But your attempt to discredit and insult are too. Read pages 43 and 44 of "From Beginner to Bubka and Isenbayeva too". The illustrator maps three types energy throughout with the use of a graph.

If I thought you knew anything about what I'm talking about, I might be offended. But you're just a barnacle on the old hull. Give another cheer for deal old friends from their coat tails for me...it much easier than learning and understanding science...

Will
https://www.youtube.com/watch?v=ZkDF3pmaIOo
https://www.youtube.com/watch?v=DqSaQkNjyWk
http://www.physicsclassroom.com/class/w ... lum-Motion

[KirkB]

Re the science, I continue to encourage an open dialogue.

Less insults and more science, please.

Kirk

[grandevaulter]

If I thought you knew anything about what I'm talking about, I might be offended. But you're just a barnacle on the old hull. Give another cheer for deal old friends from their coat tails for me...it much easier than learning and understanding science..

According to your sources above,the force of gravity on the pendulum is nearly totally predictable, it becomes negligible. They state that tension is the least predictable, put a living person on a flexible pole that bends. Yep Will we're way over our heads. There is also the element of friction and the effect caused by the pendulum passing through air. We may join forces to evaluate the aerodynamic properties and the application of physics of Renaud's skin tight shorts.

So I'll take a victory lap and cheer from the coat tails of my dear friends. I'll wait for you to post how vaulters that throw their heads pertain to this subject. Here's another head thrower from this weekend. http://www.bostonglobe.com/sports/2015/ ... EST_RATING

[PVstudent]

Readers please re read pages 3,4 and 5 and assess in your own opinion if Will is saying something new or unknown by coaches.

In fact these pages show the simple math, free-body diagrams with respect to the pendular motion of a vaulter with respect to the "Gravity Force Vector" ie that force which will cause the vaulter total body COM to be accelerated vertically downward (Radially directed towards the earth's centre along the straight line connecting the mass centre of the earth to the mass centre of the vaulter at a rate of velocity change (acceleration) of - 9.8 m/s/s approximately).

There is nothing unknown, or new or novel in using the components of the pendular tension force to obtain the tangential acceleration of the COM of the vaulter ie the pendulum "Bob".

If on re reading my work you agree with Will that we coaches don't understand what he is trying to say please explain it to us!

The basic principles of Classical Newtonian physics are just that. No human moving below the speed of light can defy those principles.

When the observation is carried out the motion of the vaulter's COM does not behave as Will's "Thought Experiment Hypothesis" would have us believe.

There is no "divination" about the measurements used to trace the path of the parameter Will's hypothesis predicts that it should take.

Put bluntly Will's Hypothesis appears to be on very shaky ground from both a theoretical and empirical point of view.

But according to Will we are too ignorant to understand so, I for one, must remain unenlightened.

Being a member of a cult of "Cargo Cult Scientists" is only fitting for us ignoramuses in Will's revered opinion!

[PVDaddy]

I believe lavillenie intentionally presses up with the bottom hand to lower his COG.
I believe lavillenie relaxes his thumb grip with his bottom hand so that it is resting on his fingers. This also lowers his COG some but I believe he dies this mostly to allow for a more free pole rotation.

[KirkB]

I believe lavillenie relies on his thumb grip with his bottom hand so that it is resting on his fingers. This also lowers his COG some but ...

This is pure speculation, and has no scientific basis. Even if true, so what? So what if his CoM is lower for a split second?

This trivial detail adds nothing to this discussion.

... I believe he does this mostly to allow for a more free pole rotation.

More useless speculation. We have already debunked the theory that "free pole rotation" (which PVDaddy thinks means the pole twisting to the corner of the box) is an important aspect of modern fiberglass vaulting. There is no scientific basis for this speculation.

Unless he's talked to RL or someone in his inner circle about this munitia, it's less than useless info to us.

These "beliefs" of PVDaddy's add nothing to the topic of this thread.

Let's stick to theories and "beliefs" that are scientifically explainable and provable!

Kirk