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TeamTermin wrote: In your discussions, one of the variables we measured that I didn’t see mentioned was the stride frequency while going down the runway.

I think stride frequency is important ... very important ... but it's just not the focus of this thread. There's a few other threads going on that talk about that ... albeit not in relation to video metrics or Dartfish.

One of the focuses of this thread is to fill the void created by Linthorne when he ASSUMES a flat 1.00m pushoff for ALL elite vaulters. These are Phase 2 and Phase 3 issues, where we're breaking new ground.

In Phase 1, all we need to do for now is repeat what's already quite common ... to catch the speed of the vaulter near the end of his run ... say the last 5 meters ... but especially between Frame -1 and Frame 0.

Then, when we ANALYZE the vids, comparing one vaulter to another, etc, we might see that one vaulter's run speed is faster than another's. So then, we might want to dig deeper (as you suggest) to analyze stride frequency and stride length. Just search with keywords "stride frequency".

It's also interesting to know that we can analyze stride frequency with Dartfish. I would be VERY interested in hearing about the other PV metrics that you captured, and how you compared or analyzed them.

DJ has given me some vid that compares 2 elite vaulters side-by-side on Dartfish. I'll post that soon.

Thanks for your input, TeamTermin!

Kirk

hye

Kirk.. did or can we address the point of "maximum pole bend" and it's relationship to the "back flat" to the runway??..

or was/is it in here somewhere and i maybe didn't read everything...

i think the way you are putting this together can get us all on the same page.. when we start comparing information..

and as I stated before the “picture” can give you the “where” but not the how. The time and distance can give us an indication of the “application of force” and the picture gives us an idea of where the mass is in relationship to those factors…

just as in a sprint stride, math tells us “on paper” that a shorter faster stride is equal to a longer slower stride.. but in reality we know that “foot/body mass” position in relationship to the ground contact time (time and distance) has to have a “compatible relationship.. picture to speed of movement and distance traveled…

just like a “tuck” (body rotation) in itself “looks” very inefficient, but if the tuck is very fast for the distance covered it will add force…

my own statements sound confusing .. even to me.. but hopefully what you are doing here will put some light on how joe dial could jump extremely high with his physical characteristics, “seemingly” with a very different technique of other vaulters who are considered to have a superior technique..

T-mack fits into this also.. and I don’t want and agreement to ensue from the following statements.. I want thought and consideration of the physics involved so that we can begin to have better understanding..

This is my statement……………..

What I think this process will show is how tim mack could have a takeoff angle that was considered to “flat”, a takeoff that was not quite “out” (free) enough and a bend that was considered a “squashing” of the pole… yet his efficiency rating comes out at the top everytime..

Like I said this is not here for argument…….. it is to use this process to have the answers…

dj

dj wrote: ... did or can we address the point of "maximum pole bend" and it's relationship to the "back flat" to the runway??..

We don't have that covered yet, but I think we should. I did mention the "flat back" position, but not the "max bend" position. To me, these are 2 very difficult frames to find on a PV vid. The "flat back" position is usually not a single frame ... it's up to 10 different frames on the intermediates (14-foot range) vaulters that I've looked at recently. So which one do you choose as the "flat back" frame? It's almost like it's a phase on it's own, which is ideally a single frame, but may stretch to up to 10 frames or more (for inefficient vaulters). That in itself is a metric, I guess.

Any suggestions on how to identify the max bend frame?

dj wrote: ...just like a “tuck” (body rotation) in itself “looks” very inefficient, but if the tuck is very fast for the distance covered it will add force…

Yes. It's not the tuck per se that causes a loss of energy ... it's the PAUSING in that position, I think. My thinking is that despite the various models, techniques, and styles, all vaulters must vault according to the laws of physics, and the continuous chain theory is an important part of that. As long as your body keeps moving ... quickly ... and in a "good" direction (which varies by model, technique, or style) ... then it's all good. By capturing the amount of time it takes in each phase, the Video Metrics data and formulae should be agnostic to all these differences.

dj wrote: it is to use this process to have the answers…

Yes. Objectively ... not subjectively!

Vaulters vault the way they vault. Video Metrics can be used to recognize ... and try to explain the similarities and differences of disparate vaulters ... using the time, distance, and speed measurements of each phase.

Kirk

It's also interesting to know that we can analyze stride frequency with Dartfish. I would be VERY interested in hearing about the other PV metrics that you captured, and how you compared or analyzed them.

Kirk

We also measured elapsed time from the pole plant to left hand release and right hand release. This measure also revealed quite a bit of variability. Most of the video we had of the subject was clearing the height, but luckily we had two examples of where the subject didn’t clear the height.

If you just looked at a table of elapsed time of left and right hand release times, and didn’t know which jumps were cleared, I honestly think it would be hard to identify any real trend.

Again, if any of you would like some assistance trying to doing some calculations…would be happy to take a look….

Here's a thread that just started today regarding the same kind of video analysis that we're talking about on this thread ...

http://www.polevaultpower.com/forum/viewtopic.php?f=38&t=17362&p=124534#p124534

Of the 9 "PARAMETERS OF THE VAULT" that Jagodin chose to analyze, 5 of them concern the velocity of different vault parts, 2 concern angles (I'm not sure what's meant by "Angle height from ground level"), and the last 2 are the well-known pushoff and flex metrics.

These are all candidates for our Video Metrics, although to keep things simple we might want to omit the "angle at pole release" metric ... and maybe the other angle one ... whatever that is.

I'll have to study the "PARAMETERS OF THE SUPPORT PHASES" more to figure out what's meant there, but I particularly like the ANGULAR VELOCITIES and the VELOCITY OF THE TAKEOFF LEG (separated by horizontal and vertical).

I'm not sure how we can measure the angular velocities, but we should take a look at that. Any ideas?

For the takeoff leg velocity, I don't know that it's necessary to split it into horz and vert. I'm thinking that just the speed of the ankle at the Whip is the key metric to capture trail leg "effectiveness".

Thoughts?

Kirk

On ths web page http://www.thefreelibrary.com/Pole+Vault's+Education+Initiative-a0107698160, they mention a couple things related to analyzing PV videos ...

... Phase 3 is an educational program that will be a trouble-shooting program for the pole vault. It will show approximately 40 of the most common mistakes in the event, based on landing zones--an indicator of serious technical problems.

The computer will allow the coach or athlete to determine the zone in which the vaulter landed and decide the most common errors that may have caused the problem. After the error choice has been made, the program will move to a video of a vaulter actually performing the same error, allowing the coach to visually compare his vaulter's error to that of the video vaulter in error.

On the same computer page, a video will show the proper technique of an ideal vault and a video of the corrected vaulter in a stick-figure kinetic pertaining to or producing motion. view performing the same vault. All three videos will run simultaneously in slow motion, and can be placed in stop-action or run one at a time. An audio description of the key points as well as the correction of each problem will also be given.

This CD will be produced in mass quantities (approx. 18,000 copies) and distributed to every high school, college, and university that participates in the pole vault within the US free of charge.

The three-year project is well underway. ...

My first point is rather obvious ... it's a good idea to watch exactly where the vaulter lands in a vid, and infer from there what MIGHT have gone wrong (if anything).

Secondly, the idea of using a super-imposed stick-figure for video analysis sounds good. Since this page was pushlished in 2003, I wondering whether or not it's come to fruition as planned? Did every coach in the US HS and college system receive their copies?

Kirk

Here are some good resources regarding video analysis:

http://www.usatf.org/groups/coaches/lib ... rtfish.pdf
http://www.usatf.org/groups/coaches/lib ... ngraph.xls
http://www.usatf.org/groups/coaches/lib ... ngraph.xls

To find the max bend frame, couldn't you just look at chord length?

I haven't posted on this thread for awhile, and some of you aren't aware of how to convert your YouTube vids to QuickTime, so that they can be watched frame-by-frame.

In an earlier post, I mentioned Moyea, so here's how to install the free Moyea software that does this ...

1. Download the free Moyea YouTube FLV Downloader product from here: http://www.moyea.com.
2. Also download their FLV to Video Converter Pro 2 (their free trial is free).
3. Paste your YouTube URL into the FLV Downloader product, and save the vid to your disk drive. This vid is still in the "Flash Video" (FLV) format, which is the format that YouTube uses.
4. Use the FLV to Video Converter product to convert to "QuickTime" (MOV) format.
5. If you don't already have QuickTime installed, download it (free) from this Apple site: http://www.apple.com/quicktime/download/.
6. Run your vid on QuickTime. You can now use the left-arrow and right-arrow buttons to step thru your vid frame-by-frame!

There's many other free video downloaders and converters on the web. I just found Moyea easiest to install and use. If there was a single product that does both the download and the conversion from FLV to MOV in a single step, that would be even easier ... but I didn't find any such product. If anyone else finds any other similar products that work for them, please post here ... for everyone's benefit.

Kirk