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Elzinator
October 1st 04, 01:10 PM
Related to the thread on motor patterns and learning, swimming stroke
goes full circle: from I-pull to S-pull, back to I-pull. So, if you
have changed your pull (like I did in the early '80's) from I- to
S-pull, you can change it back again!

ENGINEERING OF SPORT MEETING:
Pulling Straight to the End of the Pool
Adrian Cho

DAVIS, CALIFORNIA--From 13 to 16 September, researchers from many
disciplines discussed sports from curling to skydiving, from table
tennis to boxing, at the 5th International Conference on Engineering
of Sport.
For decades, competitive freestyle swimmers have been taught to make
an S-shaped path when pulling their hands through the water. But
measurements and calculations now show that to generate the maximum
thrust, swimmers should pull their hands straight back through the
water, reports a mechanical engineer whose research was inspired by
his previous study of turtles.
Swimmers have been purposely doing the "S-pull" since the early 1970s,
when famed swimming coach James ("Doc") Counsilman used underwater
cameras to film elite swimmers and found that they were moving their
hand first out to the side and then back under their bodies. By moving
side to side, hands acted like little airplane wings or propeller
blades, Counsilman argued, generating hydrodynamic lift that pulled
the swimmer through the water. That lift would supplement the force
generated by simply pushing against the water with the palms. In
recent years, researchers have questioned just how large and important
the lift forces are, but the S-pull has remained a standard technique
among competitive swimmers.

However, the S-pull may not be the best pull for all races and
circumstances, says Shinichiro Ito of Japan's National Defense Academy
in Yokosuka. Using measurements of the lift and drag coefficients of
manikin hands and a computer model of a swimmer, he found that the
S-pull makes the most efficient use of energy, as it maximizes the
ratio of lift to drag. It does not, however, generate the most thrust.
Instead, Ito found, a straight "I-pull" yields more pure power.


Thorpedo away! Olympic champion Ian Thorpe pulls his hands straight
through the water.
[the image is missing here, but not the one in my head -Thorpe rules!]


Ito had already observed something similar in his study of freshwater
turtles. When paddling about leisurely, turtles wave their feet in
flourishes, doing a reptilian version of the S-pull. When frightened,
however, terrified terrapins pull their feet straight back to swim
away as fast as possible. Analysis showed that for turtles, the
sinuous movement was more efficient, Ito says, but the straight
movement produced greater thrust.
Other familiar creatures also provide living examples of the
advantages of the I-pull. Underwater video shows that Australian
swimming sensation Ian Thorpe snaps his elbow and pulls his hand
straight through the water, Ito says. Other swimmers are following the
nine-time Olympic medalist's lead, says Yuji Ohgi, a professor of
physical education at Keio University in Fujisawa, Japan. "At the
Sydney Olympics [in 2000], only Ian Thorpe had the I-shaped pull," he
says. But now, "many, many Australian swimmers do it."

Switching from S-pull to I-pull isn't easy, says Ohgi, who is also a
swimmer. Good swimmers generate power by rolling from one side of
their bodies to the other, he says, and that makes their hands move
side to side almost automatically. "The I-shaped pull is rather more
difficult than the S-shaped pull because of the rolling motion" of the
body, Ohgi says. Still, to shave every fraction of a second from their
times, more swimmers are tackling the challenging technique and
learning to swim like a frightened turtle.

From this week's issue of Science.

Steve Freides
October 1st 04, 03:08 PM
Elzi, please post this in news:rec.sport.swimming or let me know and
I'll do it.

-S-
http://www.kbnj.com


"Elzinator" > wrote in message
om...
> Related to the thread on motor patterns and learning, swimming stroke
> goes full circle: from I-pull to S-pull, back to I-pull. So, if you
> have changed your pull (like I did in the early '80's) from I- to
> S-pull, you can change it back again!
>
> ENGINEERING OF SPORT MEETING:
> Pulling Straight to the End of the Pool
> Adrian Cho
>
> DAVIS, CALIFORNIA--From 13 to 16 September, researchers from many
> disciplines discussed sports from curling to skydiving, from table
> tennis to boxing, at the 5th International Conference on Engineering
> of Sport.
> For decades, competitive freestyle swimmers have been taught to make
> an S-shaped path when pulling their hands through the water. But
> measurements and calculations now show that to generate the maximum
> thrust, swimmers should pull their hands straight back through the
> water, reports a mechanical engineer whose research was inspired by
> his previous study of turtles.
> Swimmers have been purposely doing the "S-pull" since the early 1970s,
> when famed swimming coach James ("Doc") Counsilman used underwater
> cameras to film elite swimmers and found that they were moving their
> hand first out to the side and then back under their bodies. By moving
> side to side, hands acted like little airplane wings or propeller
> blades, Counsilman argued, generating hydrodynamic lift that pulled
> the swimmer through the water. That lift would supplement the force
> generated by simply pushing against the water with the palms. In
> recent years, researchers have questioned just how large and important
> the lift forces are, but the S-pull has remained a standard technique
> among competitive swimmers.
>
> However, the S-pull may not be the best pull for all races and
> circumstances, says Shinichiro Ito of Japan's National Defense Academy
> in Yokosuka. Using measurements of the lift and drag coefficients of
> manikin hands and a computer model of a swimmer, he found that the
> S-pull makes the most efficient use of energy, as it maximizes the
> ratio of lift to drag. It does not, however, generate the most thrust.
> Instead, Ito found, a straight "I-pull" yields more pure power.
>
>
> Thorpedo away! Olympic champion Ian Thorpe pulls his hands straight
> through the water.
> [the image is missing here, but not the one in my head -Thorpe rules!]
>
>
> Ito had already observed something similar in his study of freshwater
> turtles. When paddling about leisurely, turtles wave their feet in
> flourishes, doing a reptilian version of the S-pull. When frightened,
> however, terrified terrapins pull their feet straight back to swim
> away as fast as possible. Analysis showed that for turtles, the
> sinuous movement was more efficient, Ito says, but the straight
> movement produced greater thrust.
> Other familiar creatures also provide living examples of the
> advantages of the I-pull. Underwater video shows that Australian
> swimming sensation Ian Thorpe snaps his elbow and pulls his hand
> straight through the water, Ito says. Other swimmers are following the
> nine-time Olympic medalist's lead, says Yuji Ohgi, a professor of
> physical education at Keio University in Fujisawa, Japan. "At the
> Sydney Olympics [in 2000], only Ian Thorpe had the I-shaped pull," he
> says. But now, "many, many Australian swimmers do it."
>
> Switching from S-pull to I-pull isn't easy, says Ohgi, who is also a
> swimmer. Good swimmers generate power by rolling from one side of
> their bodies to the other, he says, and that makes their hands move
> side to side almost automatically. "The I-shaped pull is rather more
> difficult than the S-shaped pull because of the rolling motion" of the
> body, Ohgi says. Still, to shave every fraction of a second from their
> times, more swimmers are tackling the challenging technique and
> learning to swim like a frightened turtle.
>
> From this week's issue of Science.

Lee Michaels
October 1st 04, 03:26 PM
"Elzinator" wrote
>
> Ito had already observed something similar in his study of freshwater
> turtles. When paddling about leisurely, turtles wave their feet in
> flourishes, doing a reptilian version of the S-pull. When frightened,
> however, terrified terrapins pull their feet straight back to swim
> away as fast as possible. Analysis showed that for turtles, the
> sinuous movement was more efficient, Ito says, but the straight
> movement produced greater thrust.

Although this is very interesting, I wonder what the speed differnce is
between a turtle's efficiency stroke and it's mad dash stroke. It would
seem that anything that could eat it would have no trouble catching it no
matter which stroke it used.

Proton Soup
October 1st 04, 03:59 PM
On Fri, 01 Oct 2004 14:26:04 GMT, "Lee Michaels"
> wrote:

>
>"Elzinator" wrote
>>
>> Ito had already observed something similar in his study of freshwater
>> turtles. When paddling about leisurely, turtles wave their feet in
>> flourishes, doing a reptilian version of the S-pull. When frightened,
>> however, terrified terrapins pull their feet straight back to swim
>> away as fast as possible. Analysis showed that for turtles, the
>> sinuous movement was more efficient, Ito says, but the straight
>> movement produced greater thrust.
>
>Although this is very interesting, I wonder what the speed differnce is
>between a turtle's efficiency stroke and it's mad dash stroke. It would
>seem that anything that could eat it would have no trouble catching it no
>matter which stroke it used.

If while walking through the woods, you and a friend are chased by a
bear, you do not need to be faster than the bear, just faster than
your friend.

-----------
Proton Soup

"Homo sapiens non urinat in ventum."

Tiger Hillside
October 1st 04, 05:06 PM
On Fri, 01 Oct 2004 09:59:44 -0500, Proton Soup >
wrote:

>On Fri, 01 Oct 2004 14:26:04 GMT, "Lee Michaels"
> wrote:
>
>>
>>"Elzinator" wrote
>>>
>>> Ito had already observed something similar in his study of freshwater
>>> turtles. When paddling about leisurely, turtles wave their feet in
>>> flourishes, doing a reptilian version of the S-pull. When frightened,
>>> however, terrified terrapins pull their feet straight back to swim
>>> away as fast as possible. Analysis showed that for turtles, the
>>> sinuous movement was more efficient, Ito says, but the straight
>>> movement produced greater thrust.
>>
>>Although this is very interesting, I wonder what the speed differnce is
>>between a turtle's efficiency stroke and it's mad dash stroke. It would
>>seem that anything that could eat it would have no trouble catching it no
>>matter which stroke it used.
>
>If while walking through the woods, you and a friend are chased by a
>bear, you do not need to be faster than the bear, just faster than
>your friend.

And just hope that the bear was not walking with his friend.

Keith Hobman
October 1st 04, 08:08 PM
In article >,
(Elzinator) wrote:

> Related to the thread on motor patterns and learning, swimming stroke
> goes full circle: from I-pull to S-pull, back to I-pull. So, if you
> have changed your pull (like I did in the early '80's) from I- to
> S-pull, you can change it back again!
>
> ENGINEERING OF SPORT MEETING:
> Pulling Straight to the End of the Pool
> Adrian Cho
>
> DAVIS, CALIFORNIA--From 13 to 16 September, researchers from many
> disciplines discussed sports from curling to skydiving, from table
> tennis to boxing, at the 5th International Conference on Engineering
> of Sport.
> For decades, competitive freestyle swimmers have been taught to make
> an S-shaped path when pulling their hands through the water. But
> measurements and calculations now show that to generate the maximum
> thrust, swimmers should pull their hands straight back through the
> water, reports a mechanical engineer whose research was inspired by
> his previous study of turtles.
> Swimmers have been purposely doing the "S-pull" since the early 1970s,
> when famed swimming coach James ("Doc") Counsilman used underwater
> cameras to film elite swimmers and found that they were moving their
> hand first out to the side and then back under their bodies. By moving
> side to side, hands acted like little airplane wings or propeller
> blades, Counsilman argued, generating hydrodynamic lift that pulled
> the swimmer through the water. That lift would supplement the force
> generated by simply pushing against the water with the palms. In
> recent years, researchers have questioned just how large and important
> the lift forces are, but the S-pull has remained a standard technique
> among competitive swimmers.
>
> However, the S-pull may not be the best pull for all races and
> circumstances, says Shinichiro Ito of Japan's National Defense Academy
> in Yokosuka. Using measurements of the lift and drag coefficients of
> manikin hands and a computer model of a swimmer, he found that the
> S-pull makes the most efficient use of energy, as it maximizes the
> ratio of lift to drag. It does not, however, generate the most thrust.
> Instead, Ito found, a straight "I-pull" yields more pure power.
>
>
> Thorpedo away! Olympic champion Ian Thorpe pulls his hands straight
> through the water.
> [the image is missing here, but not the one in my head -Thorpe rules!]
>
>
> Ito had already observed something similar in his study of freshwater
> turtles. When paddling about leisurely, turtles wave their feet in
> flourishes, doing a reptilian version of the S-pull. When frightened,
> however, terrified terrapins pull their feet straight back to swim
> away as fast as possible. Analysis showed that for turtles, the
> sinuous movement was more efficient, Ito says, but the straight
> movement produced greater thrust.
> Other familiar creatures also provide living examples of the
> advantages of the I-pull. Underwater video shows that Australian
> swimming sensation Ian Thorpe snaps his elbow and pulls his hand
> straight through the water, Ito says. Other swimmers are following the
> nine-time Olympic medalist's lead, says Yuji Ohgi, a professor of
> physical education at Keio University in Fujisawa, Japan. "At the
> Sydney Olympics [in 2000], only Ian Thorpe had the I-shaped pull," he
> says. But now, "many, many Australian swimmers do it."
>
> Switching from S-pull to I-pull isn't easy, says Ohgi, who is also a
> swimmer. Good swimmers generate power by rolling from one side of
> their bodies to the other, he says, and that makes their hands move
> side to side almost automatically. "The I-shaped pull is rather more
> difficult than the S-shaped pull because of the rolling motion" of the
> body, Ohgi says. Still, to shave every fraction of a second from their
> times, more swimmers are tackling the challenging technique and
> learning to swim like a frightened turtle.
>
> From this week's issue of Science.

It seems athletics tend to follow a 'what is the premier athlete doing',
with callous disregard for individual variation.

So this is a case where science has disproven pragmatic coaching doctrine,
right?

Helgi Briem
October 4th 04, 10:12 AM
On Fri, 01 Oct 2004 13:08:55 -0600, (Keith Hobman)
wrote:

>> Switching from S-pull to I-pull isn't easy, says Ohgi, who is also a
>> swimmer. Good swimmers generate power by rolling from one side of
>> their bodies to the other, he says, and that makes their hands move
>> side to side almost automatically. "The I-shaped pull is rather more
>> difficult than the S-shaped pull because of the rolling motion" of the
>> body, Ohgi says. Still, to shave every fraction of a second from their
>> times, more swimmers are tackling the challenging technique and
>> learning to swim like a frightened turtle.
>>
>> From this week's issue of Science.
>
>It seems athletics tend to follow a 'what is the premier athlete doing',
>with callous disregard for individual variation.
>
>So this is a case where science has disproven pragmatic coaching doctrine,
>right?

This is old news. Swimming coaches and scientists threw
out the S-pull years ago based on analysis of what swimmers
were really doing. Good coaches haven't taught S-pulling for
at least 5 years. The pull is curved, yes, but elite swimmers
are straightening it out as much as possible given the movement
of the body. The better they are, the more they can straighten it.

--
Helgi Briem hbriem AT simnet DOT is

"Don't worry about it, son. God is just messing with your head."

elzinator
October 5th 04, 03:37 AM
On Mon, 04 Oct 2004 09:12:09 +0000, Helgi Briem wrote:
>On Fri, 01 Oct 2004 13:08:55 -0600, (Keith Hobman)
>wrote:
>
>>> Switching from S-pull to I-pull isn't easy, says Ohgi, who is also a
>>> swimmer. Good swimmers generate power by rolling from one side of
>>> their bodies to the other, he says, and that makes their hands move
>>> side to side almost automatically. "The I-shaped pull is rather more
>>> difficult than the S-shaped pull because of the rolling motion" of the
>>> body, Ohgi says. Still, to shave every fraction of a second from their
>>> times, more swimmers are tackling the challenging technique and
>>> learning to swim like a frightened turtle.
>>>
>>> From this week's issue of Science.
>>
>>It seems athletics tend to follow a 'what is the premier athlete doing',
>>with callous disregard for individual variation.
>>
>>So this is a case where science has disproven pragmatic coaching doctrine,
>>right?
>
>This is old news. Swimming coaches and scientists threw
>out the S-pull years ago based on analysis of what swimmers
>were really doing. Good coaches haven't taught S-pulling for
>at least 5 years. The pull is curved, yes, but elite swimmers
>are straightening it out as much as possible given the movement
>of the body. The better they are, the more they can straighten it.

One of the issues, which Lyle mentioned during a phone conversation
yesterday, is the shoulders and RC irritation. The straight pull kills
my shoulders. I was taught the S-pull at OSU by a swim coach (had to
unlearn the straight pull and relearn the S-pull), and the first thing
I noticed was less shoulder irritation. I've since modified it to a
hybrid between the two. Which for me is the strongest of the three.

(he also told me that same thing my HS coach told me: my scissor kick
sucks ass)

Maybe Lyle could offer some feedback that he received on this article
from a competitive swimmer. I thought it was interesting.


Beelzibub

"Modern man must rediscover a deeper source of his own spiritual life. To do this,he is obligated
to struggle with evil, to confront his own shadow, to integrate the devil."
- Carl Jung