Dropping the lead knee - time for a retrospective?

[KirkB]

After watching the CBC highlights of the 2008 Olympics today, I'm beginning to wonder if dropping the lead knee is actually more optimal that keeping it up?

Steve Hooker, Evgeny Lukyanenko, and Denys Yurchenko (Gold, Silver, Bronze) all drop their lead knee - to varying degrees.

That's certainly not the way I vaulted, and when I watched Wolfgang Nordwig win the 1972 Olympics Gold with a drop-the-lead-knee technique, I considered him just super-human. Mere mortals don't have the gut strength to let the knee drop, then quickly pull it up again in time for a strong, smooth extension. To me, "pulling it up again" was a strength move fraught with all kinds of system leakage.

Personally, I rationalized that I didn't have the gut strength or the speed to let my lead knee drop, and then pull it up again. I wanted to get upside down (inverted) as early as I could on the pole. Dropping the lead knee was counter-intuitive to that thinking.

For the record, Nordwig's technique was quite unique back then. To my knowledge, the rest of us all kept our lead knees up. I suppose Bob Seagren (USC) might have been the one that led the charge on this, but I studied the films of Jon Vaughn (UCLA) more than any other vaulter, and he emphasized a very high "lead knee up" technique.

Even through the next 3.5 decades, it seems that keeping the lead knee up was the predominant technique. The name Bubka comes to mind.

But hey, how can you argue with success? Here we have all 3 medalists dropping the lead knee!

Hooker:
When I first watched his vids, I didn't notice much of a lead knee drop. Recently, I have. Is it my imagination, or is Parnov morphing his technique to become a "lead-knee-dropper"?

Lukyanenko:
I first saw his vids a month or 2 ago, and was surprised at how he DELIBERATELY dropped his lead knee. I knew why - it's been quite well documented for 4 decades. Believers in this technique do it to put more energy into the pole. The lower the athlete's CoG whilst the pole is bending, the more kinetic energy there is to transfer to the pole's potential energy. Then on recoil, the more kinetic energy is returned. But what I noticed about Lukynenko that I didn't notice about Hooker or Nordwig was that he actually SWUNG both legs up into a very nice inversion. Not quite as nice as Hooker, IMO, but still quite "smooth". And really, gymnasts have no trouble swinging both legs together - that's the natural way to swing. A one-legged swing isn't as natural. So I began to think that maybe he's got something here.

Yurchenko:
I never saw him vault before until today, but he's also clearly dropping the lead knee. I think there may be more as well (mentioned on this morning's play-by-play), but they weren't shown on CBC today.

I'm not yet convinced enough that I would coach anyone that way, but I am at least no longer discarding this technique as being sub-optimal.

Maybe this year's Olympic medalists are on to something?

Kirk


Kirk

[powerplant42]

Thanks, you just spoiled the results for me... I've been wondering this lately as well. I am not yet totally sold on the idea though, not even close, but I am beginning to switch perspective a little bit. I believe that this MAY be a case of an individualized aspect of technique, where a certain swing type may be best for certain athlete's physical traits. I need more time to ponder... I'll come back with my thoughts tomorrow.

[powerplant42]

It's okay, I know you didn't mean to spoil it.

I am back with my thoughts: The lead leg should not be dropped. Period. Think about how it affects swing speed. Think about how swing speed affects speed coming off the pole. Would you rather be moving slowly on a big bend or a lot quicker on a slightly smaller one? The only reason that stiff polers used a double leg swing is because they did not need speed to carry them upward off of the pole, they only needed to go a foot or so over their grip. This ties in very nicely with the inversion paradox that I've been talking about...

[KirkB]

Powerplant, I think you may be a little hasty in coming to your conclusion that dropping the lead knee is bad technique.

First of all, you've commented twice already, but I hadn't even re-posted my opening question, after hiding it so as to not spoil the Olympic M PV results from anyone until the Olympics were over. So I'm not so sure you really understood the question that I posed. I can restate it if you're confused, but I think you're just hasty - not confused.

Secondly, I'm actually not looking for anyone that's a "high lead knee" proponent to draw the same conclusion that they've always drawn - that dropping the lead knee is bad. I'm also a proponent of that "theory", and quite frankly, I'm thinking that I don't really understand enough about the REASON why some elite vaulters drop their lead knee. I'd like to hear from them, their coaches, or their fans and followers - that truly understand their rationale.

I am assuming that they do it for a good reason - I just don't understand that reason well enough to form my own (new) opinion about it. I want to know more about the pros as well as the cons. I won't get that from a high-lead-knee bigot (like myself).

I exclude the possibility that they drop their lead knee because they lack the leg and gut strength to hold it up. While that may be a "valid excuse" for a high schooler, by the time you get to the elite level, you should have sufficient strength. Or conversely, if you don't have sufficient strength, you won't become an elite vaulter.

Powerplant, you have simply reiterated everything that I've always believed. I'm not looking for reinforcement of my "old" ideas. I'm looking for "new" ideas - new insights into the science of why dropping the lead knee is good.

To repeat my original question: All 3 medalists drop their lead knee. Is this just coincidence, or are they on to something?

Kirk

[golfdane]

Dropping the lead knee after take-off, will lower the relative position of the CoG to your body. The trajectory of the CoG is unaffected. Since it lowers the relative position of the CoG, will your top hand gain height.
The dropping of the knee will facilitate loading of the pole, but slows down the swing (I seem to recall, that Lukyanenko drops the knee, but it's back up when he passes the chord of the pole).

I'm still undecided whether I'd advocate it. Lukyanenko seems to make good use of it, but he hasn't jumped 6.14m. Then again, he's not Bubka

[decanuck]

Remember that the pole vault is an interaction between two swinging pendulums:
1) the pole swinging from a plant position to vertical (hopefully) about its tip in the box, and
2) the vaulter swinging from plant position to vertical (hopefully) about his or her hands (initially), then shoulders (after the vaulter passes the cord of the pole).

These pendulums act in opposition such that any action that causes an increase in rotational speed of the one will cause a decrease in rotational speed of the other. Dropping the lead knee causes the vaulter's centre of mass to lower slightly, thereby increasing the swinging speed of pendulum #1. At the same time, the dropping knee puts the vaulter's centre of mass further away from his or her hands, thereby slowing the swinging speed of pendulum #2.

The net effect is that a dropped leg allows you to grip higher but makes it more difficult to invert. The the difficulty of inversion can be mitigated by breaking at the hips and knees through the inversion phase, shortening the axis of rotation and speeding inversion (pendulum #2). But, like the knee drop, this action has an opposite effect on pendulum #1 and will slow pole speed and the penetration of the vaulter/pole system. For this reason, it can only be done AFTER the pole has been driven into the pit somewhat.

If you consider stiff-pole technique, lead knee dropping is without a doubt a benefit. On flexible poles it is less clear. The reason is that the action of actively inverting (i.e. forcefully PULLING one's self upside-down) on a flexible pole causes the pole to bend more, thereby storing energy that can be exploited later--energy cannot be stored in a straight pole. The ideal inversion occurs with a straight body because the force generated by pulling a cantilevered body to vertical is much greater than that generated by pulling a tucked body. This is merely because of leverage. It is for the same reason that a 20ft pole, held at horizontal, feels much heavier than a 10ft pole of the same weight.

The ultimate question concerning lead knee dropping then becomes: to what extent is the increase in grip worth the opportunity cost of a weaker inversion, or worse still, an inversion that does not complete in time for the vaulter to line up with the recoiling pole. I think the answer changes from vaulter to vaulter and even for the same vaulter it varies by grip/pole combination and even for the same grip and pole it changes from jump to jump, IMHO. Even during some of Bubka's jumps his lead knee appeared to drop a minor amount momentarily.

[Rhino]

Excellent post, Decanuk! Several years ago I downloaded an extensive article by Dr. Spencer Chang who, if I remember right, was a proponent of dropping the lead knee. I am pretty certain the I got the link from somewhere on this board.

However, since Powerplant has pronounced the action "BAD", I will strive to get my right knee as high as I can!

[KirkB]

I would love to hear from someone that drops the lead knee BY INTENT.

Someone like Paul Litchfield - who I watched at the Alki Beach Vault this year.

In Eugene, I saw a UO (U of Oregon) vaulter vault like Lukyanenko (albeit under 5.00m). I didn't catch his name, but he was certainly dropping it by intent.

We should not fear criticism, just because we're not following the Petrov model.

Based on the succes of the Olympic medalists, there's some momentum in favor of dropping the knee, so let's hear from you!

If you're a lead-knee dropper, how do you counter the issue of a slower inversion?

Kirk

[vaultman18]

After watching the CBC highlights of the 2008 Olympics today, I'm beginning to wonder if dropping the lead knee is actually more optimal that keeping it up?



Hooker:
When I first watched his vids, I didn't notice much of a lead knee drop. Recently, I have. Is it my imagination, or is Parnov morphing his technique to become a "lead-knee-dropper"?


Kirk

It is indeed just your imagination.

[volteur]

After watching the CBC highlights of the 2008 Olympics today, I'm beginning to wonder if dropping the lead knee is actually more optimal that keeping it up?

Hooker:
When I first watched his vids, I didn't notice much of a lead knee drop. Recently, I have. Is it my imagination, or is Parnov morphing his technique to become a "lead-knee-dropper"?

Kirk

It is indeed just your imagination.

I asked Steve about this change and he said they hed been working on trying to correct it,but i sensed not seriously as he was a little evasive about it. Mainly he was excited about how long Bubka spends on the side of the pole during inversion and how to do that. I believe it is because Bubka is there earlier combined with the fact he stays there longer, as he is actively pulling at that stage whereas most vaulters are reaching that point too late and so have to accelerate to catch up with the pole. Bubka is early enough to gain the advantage of a longer pull. You could also say he gets ahead of the pole earlier and faster because of this.

Getting back to the Hooker thing this was a problem Burgess had and i remember Steve Rippon trying to correct it in the early days - when Paul was about 16. Paul was a national gymnastic medallist before vaulting and got an amazing advantage from the scoop or kip he could create on the pole. I would argue he overdid this aspect and it caused him to fall behind the timing and be late for the rest of his vault but in isolation - there is probably nobody who could do that aspect better. On the high bar he was king. On the vault pole his advantage was overdone and imo became an error. Hooker trains with Burgess and maybe some gymnastic training in the gymnastics hall at WAIS there has changed Steve's basic movements. For sure Steve always had a correct knee drive position and held it as James Miller, another Rippon athlete at 5.75 did exceptionally. Steve has changed and is trying to half heartedly correct it. Now he has an Olympic Gold medal and record at 5.96 and did that on his own after he had won - amazing. If he goes to Petrov he will be the poster child for the 6.40 vault model by actually jumping it.

[VaultNinja]

Well I'm no big shot vaulter to study or criticize, but I did manage to jump 5.60m on a 15.5 flex 5m pole (which now days is a short run pole for me) dropping my lead knee dramatically.
I can only imagine that I developed this technical variation from the beginning. Where I went to high school we didn't have a pole vault coach, or any experienced vaulters in the area. So I basically taught myself how to vault and bend a pole on feel. When I watch film of myself and that lead leg drops, you can clearly see that I reload or apply extra pressure to the pole pushing it further into the pit. This in turn gives me more time to swing upside down and a better position after taking off with a step way closer than what most "models" suggest, and my hips sucked underneath my shoulders.
I have tried to correct this variation for many years, and can manage from a short run, but my body does not want to do it from full. I have also moved my step out further, and worked on getting my chest in better rather than being on my heals. I think the knee drop is a very efficient way to get upside down if you are taking off under with a stiff bottom arm. I used to be runway-side with my top hand (right hand) clear across my left hip consistently when I was in college. Jumping the same heights I am jumping now on much softer poles with lower grips. However now that I've got my step out further, and am standing up better at takeoff, I can't swing upside down to save my life because it feels so different and awkward. But I can grip high on much larger poles, and my shoulder and lower back thank me for the changes. So thats the battle I'm fighting now, and most people suggest I need to keep my knee up. Some days in practice I want to move my step closer just so I can remember what it feels like to really get inverted again. But I'm working towards something bigger. Just like a golfer......I've lost my swing.
-Paul L

[swtvault]

Dropping the lead knee is nothing more than a balance mechanism. People will drop the knee to maintain balance for the initial part of the vault, and pick it up again to help speed the rotation. The question we should be asking is what is the underlying factor for him to drop the lead knee, and what is causing it. It is not a technique people strive for or work on....it is simply an act of necessity that is predicated from technical errors. It can be caused by a heavy bottom arm (more horizontal pressure) a negative take-off angle (body angle) a late plant, or many other related things. In my opinion, athletes intuitively feel things being wrong or not quite in place, and they subconsciously make adjustments to overshadow the error. A perfect example is Nick Hysong. He does not have a dynamic swing to vertical, due in part to his extremely heavy left arm. He shortens his swing radius and breaks at the hips because he has to....he has spent too much time adding time to his swing to vertical (left arm pressure.) By breaking at the hips and shortening his swing radius he is just barely able to catch the pole before it reaches vertical. If he did not break at the hips and shorten his swing radius, the pole would certainly unbend and he would miss the ride everytime. If we wanted to, I am sure we could trace the problem back and analyze why he has excessive arm pressure due to another lack of position or balance, but that is another story. I know this is not necessarily an example of dropping the lead knee, but I believe that the principles of the issue are the same and it all boils down to athletes performing moves out of necessity to accomplish the end result.