Petrov Model vs. Lavillenie Model

[PVDaddy]

My thought is Kirk McBride has always been a wanna be.

[willrieffer]

I have clarified my position on the value of the potential energy value and curves in vaulting. This sets goals for any and all "techniques".

SInce this thread we've had Mondo take over. Doesn't take off like Bubka, doesn't swing like Bubka, doesn't exit the pole with the body technique of Bubka. So, yeah. He's routinely under. His 6.05m EC jump I have him at like a foot and a half under. So all that stuff that is at the center of the PB model, 'if you don't jump like Bubka you're losing energy' is just bunk. The commonality of Bubka and Mondo is that Mondo clears 6.2xm by a foot where Bubka cleared 6.0xm by a foot.

Bubka 10.0m/s, Lavillenie 10.0m/s, and Mondo up to 10.2m/s. And in Ke = 1/2 m velocity squared, where a little bit of velocity increase gets compounded in the square.

Per my analysis Lavillenie did everything I suggest. Punch at plant to help keep the center of mass from pendulum swinging forward and UP! His leg movements, dropping the lead leg and reaching the trail leg back work in tandem to move his center of mass down and back. He has a truncated swing where he swings a little but then rolls up into a tuck. Because swinging is simply a means to and end, that is getting the vaulters center of mass aligned with the vertical line of gravity through the top hand. The tuck also keeps the center of mass lower than Bukba's "open swing" thus conserving velocity, and also allowing the vaulter to put more work into the vault later with the 'kip up' pull through that's going to displace the vaulters com faster eg providing more work energy.

It's notable Mondo follows this model more than the PB.

Sean Francis's masters was to prove the PB model, through statistical analysis he found the opposite. That's good science.

Is Bubka's vault a bad way to vault? Not at all. It's actually easier than the ones these other two guys use. His deep body arch and trail leg reach? His com with this is back behind him outside of his body on the backside. That's driving the pole. "Staying behind the pole". You can't teach a beginner to do a quasi double leg as there isn't time to allow it. You're taking off 6' or 8' from the box you gotta go up fast! At 12' plus you gotta wait and drive the pole forward. The record that will never be broken, Mondo's U10, is a pretty normal vault, not the one he does now. He's still under!

The whole flex revolution was predicated on the fact that flex poles allowed a lower potential energy curve over straight poles. Lower gave rise to higher! Now vaulters reached near the plane of the crossbar (thus the need for "penetration" to generate a high skinny parabola over the bar) with the pole returning vertical thrust energy. It would seem you would want to maximize that. So why jump at takeoff? That was a necessity of strait pole vaulting! * I was once told very early on with fiberglass poles that the athletes were instructed to jump to prevent breakage. Yes, it reduces the pole braking force. And you can pair any technique with a corresponding pole. You want a big pole holding a lot of energy.

When my kids learn to punch and hold their com back they always immediately go through a lot of poles. And jump higher.

PV Daddy gets it. Tim McMicheal.

The human body as such is isomorphic. The physics goals I've laid out are fixed. But any number of body positions will achieve similar results.

Will

[willrieffer]

Having read through this thread again...

2. The PM is explained in more scientific terms, according to the Laws of Physics. Notice that I did not say that it is scientifically superior to the LM. It's just that there's very little documentary evidence thus far regarding the scientific merits of the LM - according to the Laws of Physics. There have been SOME attempts at explaining the LM, but to date, these attempts appear to me to be more junk science than scientifically provable explanations of the merits of the LM from a biomechanical perspective.

Ugh. I went through this with all of the notable people.

From 7th grade on I was in high track math and physics. I studied physics at Ohio State. So that's about a decade of math and physics studies. I was on the math team and twice won regional awards for math. I got a perfect 36 on the ACT physics exam and 35 on the math.

Yet a bunch of pole vault coaches with ADMITTEDLY no formal training in physics are the ones setting the table on vault physics.

They told me it would take ten years for me to be a good vault coach, but of course they can do physics without any training!

Since I officially started coaching HS I've missed the MO State meet once, the first year I transferred schools. The guy jumped 13' 6" at districts and got 5th, a mark that will usually go through. He missed the first two weeks of the season with a broken wrist and had not pole vaulted previously.

I didn't actually predict Mondo, but that someone like him was possible. Under. Doesn't use the FTO. Doesn't do the big elongated swing but "hangs" and rolls up to tuck. None of it is aligned with the PB Model. Bubka, great vaulter. Petrov great coach. But lots of great coaches are REALLY bad at the physics of the event.

There's a thing I dubbed the "magic socks" argument. I say Bubka was great because he got this pair of big black and white striped socks from Baba Yaga. You say, "That's not true. It's not scientific!" I say, "DId you see him wearing the socks?" You, "Yes, of course but..." I say, "Was he the best ever?" You, "Yes, but..." I say, "No buts! He was the greatest ever and its because, as you admitted, he wore the magic socks." This is all to say you could say anything that sounded scientific and tie it back to Bubka's performance whether it was true or not. Gormley once wrote 15 pages on his "experiment" of putting a transducer in the box to measure force. Then he measured the FTO vs a running take off. And low and behold he found that the running take off produced more force in the box..."therefore you should use the FTO because it reduces force". Well of course he didn't engage with what more force means and how it effects the vault. More force in the box means more force at the top hand. And IF the vaulter can learn to manage it, and I've explained how that can be done, and in fact Lavillenie showed us how it can be done, it means more energy going into the pole faster, a good thing scientifically explained and demonstrated.

This harkens to my other example of the rampant problem in the "folk physics" surrounding vault. More energy is better. Flex poles lose energy. Straight poles don't. So to jump higher use straight poles! All factually correct. All logically sound. But it's what's left out, that flex poles allow a different and beneficial potential energy curve over straight poles and while doing so return energy as vertical thrust near the plane of the crossbar.

Science is hard. Even people trained in it's use make mistakes. That's why most research teams are teams so that there are other questioning minds around to cover the examples I've shown and a lot of stuff I haven't covered.