Shinji's sinking legs.

[Talvi]

In many of Shinji's videos you can see that his legs begin to sink at the end of a short glide drill, as most people's do eg:
https://www.facebook.com/photo.php?v...type=2&theater

I've posted (went up like a lead ballon) about how to stop sinking legs and float, on your front or back, by lifting your hands slightly above the water surface (by creating more weight at the head side of the CoG). So it's great to find this video of Shinji demonstrating exactly this here:

https://www.youtube.com/watch?v=wsL6-rAWcLw

(especially at 1:00/1:09)

The principle Shinji is demonstrating is of course applicable applied to other aspects of the stroke.

[CharlesCouturier]

Ishhh... that's shaking hand with the devil. ;-)
I'll follow this thread with great interest.

[sclim]

Originally Posted by CharlesCouturier

Ishhh... that's shaking hand with the devil. ;-)
I'll follow this thread with great interest.

Hahaha!

Some strong opinions on balancing principles maybe being violated here, it seems! I too will follow with interest, expecting some fireworks.

[CharlesCouturier]

In short, I can at least find one huge issue with this proposal.

It assumes that it's possible, whilst swimming the freestyle (as opposed to just giving a "longest glide" demo), to keep the head higher than the level at which the water can support it, without using your hand to press water down. Honestly? With elites, I think it is very unlikely. With newbies? next to impossible.

Buoyancy is a very strong force. It's hard to struggle against it, regardless of the reason why someone might try. And even if it was indeed possible, neck pains?

[ysun29x]

I think the reason why Shinji can float with high leg is his stretch is very nice .

When he stretches his body , he shifts some waist weight upward which will make the center of gravity more closer to the center of buoyancy.

On the other hand , he is trying hard to push his chest , that's why his shoulder bade and hands are on the top of water. And then use his back and hip muscle to lift the leg up.

Check out his belly , so narrow. it is not because Shinji has so nice body shape or suck in his belly . The real reason is he is stretching his waist and shifting weight upward .

And I recommend this video. You will find some explain.

https://www.youtube.com/watch?v=oW5nE5FBPsQ

[Talvi]

Heresy leads to progress :D Surely the ill-manners of physics shouldn't give rise to poop-throwing here?

Originally Posted by CharlesCouturier

.. It assumes that it's possible, whilst swimming the freestyle (as opposed to just giving a "longest glide" demo), to keep the head higher than the level at which the water can support it, without using your hand to press water down. Honestly? With elites, I think it is very unlikely. With newbies? next to impossible.

Buoyancy is a very strong force. It's hard to struggle against it, regardless of the reason why someone might try. And even if it was indeed possible, neck pains?

Charles, I consider myself a beginner yet I find no problem arching my neck so my head is higher than the level at which the water provides maximum buoyancy. While swimming I play a lot with my head position though the angles of change there are probably very small. They just feel big. While swimming generally there is not enough time for me to feel the flotation effects of different positions - because my feel for the water etc is quite poor. However I do routinely float about, exploiting the princples Shinji (unwittingly?) demonstrates in the video, and recently discovered that you don't even need to extend your arms above your head to float. You can just raise your head! Discovering that was wierd. I imagin I resembled someone in those shots of the Dead Sea. So odd feeling my feet floating slowly upwards. All good fun, but I find also instructive, not only of the basic physics but of the horizontal feeling in the water.

[CharlesCouturier]

If you want to better understand why I am uncomfortable with this proposal, push your testing a bit further.

Try the same drill, with your head entirely up, outside the water.

[sclim]

Originally Posted by ysun29x

I think the reason why Shinji can float with high leg is his stretch is very nice .

When he stretches his body , he shifts some waist weight upward which will make the center of gravity more closer to the center of buoyancy

On the other hand , he is trying hard to push his chest , that's why his shoulder bade and hands are on the top of water. And then use his back and hip muscle to lift the leg up.

Check out his belly , so narrow. it is not because Shinji has so nice body shape or suck in his belly . The real reason is he is stretching his waist and shifting weight upward .

And I recommend this video. You will find some explain.

https://www.youtube.com/watch?v=oW5nE5FBPsQ

I am trying to follow your explanation, because I think you are making a very important point. However, I think your description is possibly confusing because in the first bolded passage, I think you are using Anatomical Language, because this is the only explanation that makes sense to me. (To "shift waist weight upward to make the centre of gravity closer to the centre of buoyancy" only makes sense if upward here means upward in relation to the anatomical body, that is, further away from his feet, or, in reference to the swimming pool, further along in the direction of travel). Am I correct in understanding what you were explaining?

In the next paragraph, I think you are more obviously using up in the sense of the surrounding or swimming pool frame of reference, where lifting the leg up means towards the action of lifting it out of the water, whereas, again in the next paragraph, I think you come back to the Anatomical Language frame of reference when you say "shifting weight upward" -- I think here you intend to mean he is shifting his weight further out away from his feet, rather than lifting it towards the water surface, or maybe even out of the water, which is maybe where Talvi is going with it.

This is not a criticism of your language skills -- I think your English is excellent btw and very clear. It is only to point out a problem that happens when describing (in any language, I'm sure, not just English ) an activity that occurs with the human body in a horizontal position: When you say "up" where are you thinking? When you say "front" where do you mean?

The potential confusion gets significantly perplexing when it occurs in the context of subtle body movements and weight shifts that the listeners don't usually encounter or think about every day, so the brain is already stretched to its limit (or, in my case, beyond!). When I ask questions or describe experiences, I have tried to address the problem by describing, where confusion may be possible, in the language of Anatomical Position; but this creates another problem, the need for further explanation and the necessity of a long boring, possibly redundant description. However, this latter problem, I feel, is better than being misunderstood, or having multiple different understandings among readers or listeners.

PS BTW, I am not making any recommendations for anyone else -- I think we all do our best to make our descriptions and questions clear to others. When any possible ambiguity arises, the one who is unsure can always ask. I guess, essentially, I am just asking, and the request for clarification is at the end of the first paragraph.

[haschu33]

I have some skepticism here when I hear or see these kind of bizarre explanations - like that given by the funny guy in the video or that what sclim quoted.

My take is very simply this: constricting muscles constricts muscles. That's it. It does not shift weight - at least not that weight in that direction what we want here. When you tense the gluteus muscles (which basically is the butt) you might see some weight shifting from the birds-eye view on a swimmer swimming on his belly. That shift is mainly from the sides to the center and back. Since it is on both sides it doesn't have a relevant effect.

Also i don't see the desired effect when bringing up the legs through muscles from the hip. It's mechanics in the water: when the feet are brought up the hip goes down.


Why can't we just say: the experience shows... and leave it there?



Anyway. Hang on in there...

[ysun29x]

Originally Posted by sclim

I am trying to follow your explanation, because I think you are making a very important point. However, I think your description is possibly confusing because in the first bolded passage, I think you are using Anatomical Language, because this is the only explanation that makes sense to me. (To "shift waist weight upward to make the centre of gravity closer to the centre of buoyancy" only makes sense if upward here means upward in relation to the anatomical body, that is, further away from his feet, or, in reference to the swimming pool, further along in the direction of travel). Am I correct in understanding what you were explaining?

In the next paragraph, I think you are more obviously using up in the sense of the surrounding or swimming pool frame of reference, where lifting the leg up means towards the action of lifting it out of the water, whereas, again in the next paragraph, I think you come back to the Anatomical Language frame of reference when you say "shifting weight upward" -- I think here you intend to mean he is shifting his weight further out away from his feet, rather than lifting it towards the water surface, or maybe even out of the water, which is maybe where Talvi is going with it.

This is not a criticism of your language skills -- I think your English is excellent btw and very clear. It is only to point out a problem that happens when describing (in any language, I'm sure, not just English ) an activity that occurs with the human body in a horizontal position: When you say "up" where are you thinking? When you say "front" where do you mean?

The potential confusion gets significantly perplexing when it occurs in the context of subtle body movements and weight shifts that the listeners don't usually encounter or think about every day, so the brain is already stretched to its limit (or, in my case, beyond!). When I ask questions or describe experiences, I have tried to address the problem by describing, where confusion may be possible, in the language of Anatomical Position; but this creates another problem, the need for further explanation and the necessity of a long boring, possibly redundant description. However, this latter problem, I feel, is better than being misunderstood, or having multiple different understandings among readers or listeners.

PS BTW, I am not making any recommendations for anyone else -- I think we all do our best to make our descriptions and questions clear to others. When any possible ambiguity arises, the one who is unsure can always ask. I guess, essentially, I am just asking, and the request for clarification is at the end of the first paragraph.

Hi sclim ,
You are right , my explanation is not clear .
Forgive me my poor english. I am Chinese , I rarely use english. I need to practice my english . Thanks for your tips.

To "shift waist weight upward to make the centre of gravity closer to the centre of buoyancy" , you are right , "upward" here means upper body in Anatomical direction.

To "lifting the leg up" ,you are right also , it means the leg is more closer to the surface of water