Comparing still frames

[varska]

Okay, here's a HS junior girl on a 13', 140 - going after a 12' bungee. On the right is Isi for comparison. Thoughts?

http://tinyurl.com/9xkk78

Thanks!

[powerplant42]

She might be leaning back a little.

The picture quality is very poor... do you have any other shots?

[KirkB]

This is a good way to compare an athlete to "the Petrov model". However, I don't know why the second pic of Isi was from a different meet. It's best to compare the frames of a single jump.

I will call the HS athlete "Varska", although I suspect that that's your name. Presumably, you're her coach. It's awkward to describe someone's vault without knowing their name, so it's Varska for now.

EDIT: I've changed her name to Allie, now that I know it.

Attempting a 12' bungee is very good for a HS Jr. female. Allie has good potential, and is doing a lot of things right. However, here's some areas for improvement ...

Keep in mind that it's as important to "look" between the frames as at the frames. You can't visually see them, of course, but you must imagine them in your mind's eye. That's because the transition from frame to frame is more important than the frame itself. i.e. how did Allie get from the previous frame to the frame you're looking at? It's the motion between each frame that's important - not the static view of the frame.

The best way to follow this analysis is to open 2 instances of this thread side-by-side, with one focused on the pics (wide enough to see both pics), and the other focused on my analysis (using the remaining width of your monitor).

Frame 1 looks like Allie's not reaching high enough with her top hand. This might be just be the frame. In the next frame, I would hope that she reaches fully. But I'm guessing that she doesn't, else you would have shown that one.

Frame 2 isn't bad in comparison to most HS female vaulters (I suppose), but in comparison to Isi, you can see that there's no stretching of the trail leg and consequent driving of the chest and lead knee. Isi is setting herself up for a great elastic position to whip from, whereas Allie isn't.

Also, it's doubtful that Allie jumped off the ground very hard. Had she jumped, she would have had a better, stretched "C" position.

Frame 3 is the most telling of all the frames. Allie has "lost it" a bit here. She has begun to swing her torso forward too far (not purposely - it's just a consequence of previous actions), too early. In comparison, Isi stays behind her pole more - in a more complete "C". However, Isi's posture isn't that much further than the previous frame, which is a superior vault (In the black top, Isi isn't under as much.)

Keep in mind that there's nothing specifically for Allie to fix in Frame 3. She needs to go back and fix the problems that I mentioned about Frames 1-2, and then Frame 3 will fix itself.

Also notice in Frame 3 that Allie's left elbow is way too close to the pole. That's a symptom only - not anything that needs to be fixed by doing something different with the left arm. Instead, the other points that I mentioned will fix this. Remember: The bottom arm should just be used for balance here - nothing more.

In Frame 4, going by the blur of the trail leg, Allie appears to have an excellent hinge action (although she's already swung to far forwards, because of Frames 1-3). It's kind of weird, but it looks like the leg closest to the camera is the lead leg, but I know that's not the case. It must be the poor quality of the pic.

In Frame 5, Allie looks comparable to Isi at first glance. However, she's not moving thru this "flat back" position nearly as quickly. This is due - of course - to the previous frames, starting with Frame 1. Again, there's nothing that she can fix here. She just needs to go back and fix the previous actions.

Frame 6 is further evidence of my analysis of Frame 5. You can't see it very well, but Allie is "stuck" in the "flat back" position, whereas Isi moves thru this position. Notice that in Frame 5, Isi is slightly lower than "flat back" and in Frame 6, Isi is slighly higher than "flat back". In comparison, Allie is "stuck" - not moving thru very quickly at all.

In Frame 7, Isi is extending nicely (due to her good swing), wheras Allie is probably "muscling" it to try to recover from the lack of momentum during the "flat back" frames. It's very telling that Isi's Center of Mass (CoM) is much closer to her top hand than Allie's. You won't see this if you look only at their upper bodies - they're about the same. But you will see this if you look at their legs. The CoM of Isi's legs put her overall CoM closer to her top hand in comparison to the CoM of Allie's legs.

Another interesting difference in Frame 7 is that Isi's bottom hand is still at the middle of her thigh, whereas Allie's bottom hand is at the bottom of her shorts. Although Isi's shorts are shorter, there's still quite a difference in body position here. I could be wrong, but I attribute this to Allie pulling too soon (muscling up - bad), whereas isi is extending her legs first (good) before she pulls with the arms. In other words, Allie is pulling too early - before she gets underneath her CoM.

In Frames 8-11, it should not be too surprising that Isi is extending almost straight up, whereas Allie is starting to flag out. Again, there's nothing to coach Allie on about this. Her flagging out is due to the loss of momentum in the previous actions. Fix the previous actions, and she'll be able to extend more straight upwards. But a softer pole might help to give Allie the confidence that she can shoot more straight upwards without stalling.

In Frame 11, Isi has a very nice inverted "I" position, whereas Allie has flagged into the bungee.

Finally, in Frame 12, Allie's lower body is already on its way down - falling onto the bungee, whereas Isi is still on her way up. Isi has yet to push with her top hand, whereas Allie cannot do so. If Allie were to push with her top hand In Frame 12, it would only rotate her more into the bungee, rather than straight up.

Please consider this a constructive critique. Although I'm critical of Allie's technique, I really think that it's unfair to compare a HS Jr. with the WR holder. To repeat, Allie is already doing a lot of things right, and she has a very good career ahead of her if she tunes up her technique.

Think of it this way ... Isi has jumped thousands of bars, whereas Allie has probably jumped only a few hundred. If Allie improves one new thing each practice (10-20 jumps), then by the time she has jumped thousands of bars, her technique could potentially be comparable to Isi's.

I think that Allie has the strength and gymnastic ability to properly execute the Petrov model. She's already more than halfway there! If I were her coach, I would focus ONLY on fixing the faults in Frames 1-2, and get those closer to Isi's technique. After that, the rest will come amazingly easy! i.e. Allie will find that she can actually excecute proper Petrov technique with less "muscle-action" and more swing than she's using now.

She should improve her technqiue of Frames 1-2 not only by vaulting, but also by various gymnastics and running/jumping drills.

Kirk

[varska]

Thanks for the the in-depth analysis. Just so you can put a name to a face, the vaulter in question is named Allie. Anyway, I can appreciate your insight that the top end problems are based on the earlier frames. Initially, I felt it was simply a matter of swinging through harder with the trail leg.

But the more I look, I can see your point.

I know the plant isn't perfect and the lower arm collapses a bit, but Allie is pretty strong and has the ability to muscle up through the latter stages to do a pretty good Isi impression. But i believe you're spot on - she needs to take the momentum into the takeoff and swing through the flat- back, rather than muscle it up.

Side note: footage always shows a collapsing lead arm. Allie knows to punch it up high, but walking that line between a nice triangle and blocking out is difficult.

Anyway, thanks again for your analysis - very good points to work on.

Jim

[KirkB]

Jim, I've edited her name to "Allie" now.

Her trail leg swing seems to be OK once she starts whipping her trail leg thru. It's just that her posture is bad prior to this. You've made this very easy to see, with the side-by-side comparison to Isi.

Isi's posture is quite good - especially in the frame when she's in the black top. The more upright your posture is when you start your hinge/swing, the more powerful it will be.

You can see this quite readily on Bubka's 6.15 WR jump too. See: New video of the Sergei Bubka World Indoor Record in Donetsk http://polevaultpower.com/forum/viewtopic.php?f=31&t=16406

EDIT: Fixed the height of Bubka's WR jump.

Kirk

[powerplant42]

(6.15)*

Get her on a high bar and have her do tap swings to get her trail leg staying straighter.

And 100% agreement with KB.