Swim Stroke Analysis Results

Expert

2547

The Woodlands, TX

Subject: RE: Swim Stroke Analysis Results

morey000 - 2012-07-05 9:01 PM

OK- here it is. A straight, deep catch is a more efficient stroke than the s-shaped pull that I learned when I was in high school.

the little caveat to this is- you need to have some pretty well developed shoulder strength to make it work.

enjoy-

http://well.blogs.nytimes.com/2012/07/04/delineating-the-perfect-swim-stroke/?ref=health

Yep. Now all we have to do is detach our body so that no other part of freestyle comes into play.

Oh, and someone needs to tell this guy he's been doing it wrong:

http://youtu.be/SuRLkXB2IBE

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Expert

2192

Greenville, SC

Subject: RE: Swim Stroke Analysis Results

i think the article is very misleading.

the article states that the study was done using the assumption that lift is important to an efficient stroke. is it, or is natural straight body position better? lift, as in getting your body up higher, forces fluid to divert under you; like an airplane wing does. obviously a straight arm stroke will do this naturally more than s-shaped stroke. the first third of the stroke is wasted pushing your arm down, and pushing your body up; the s-shape stroke focuses on attempting to divert as much of your energy towards pulling water back throughout the entire stroke; due to the s-shape nature though there is a little bit of diagonal force applied, which is why i think some swimmers have problems swimming straight, myself included.

"The better choice for human propulsion, he says, was the paddlelike deep-catch stroke, which actually produced more lift than sculling, along with a hefty dose of drag."

the article also doesn't seem to understand drag. it states that the deeper pull creates more, and that's good. this obviously is not the real world case, as drag is an impeding force, not propulsive. creating lift by pushing your body higher in the water seems to be a lot of energy that could have been spend trying to move it closer to the finish line rather than the clouds, and you are going to lose all of that momentum after the stroke when you sink right back down to the depth the sculling swimmer stays at; actually you will probably sink a little deeper due to the momentum.

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Melon Presser

52116

Subject: RE: Swim Stroke Analysis Results

Clempson - 2012-07-06 11:57 PM

i think the article is very misleading.

the article states that the study was done using the assumption that lift is important to an efficient stroke. is it, or is natural straight body position better? lift, as in getting your body up higher, forces fluid to divert under you; like an airplane wing does. obviously a straight arm stroke will do this naturally more than s-shaped stroke. the first third of the stroke is wasted pushing your arm down, and pushing your body up; the s-shape stroke focuses on attempting to divert as much of your energy towards pulling water back throughout the entire stroke; due to the s-shape nature though there is a little bit of diagonal force applied, which is why i think some swimmers have problems swimming straight, myself included.

"The better choice for human propulsion, he says, was the paddlelike deep-catch stroke, which actually produced more lift than sculling, along with a hefty dose of drag."

the article also doesn't seem to understand drag. it states that the deeper pull creates more, and that's good. this obviously is not the real world case, as drag is an impeding force, not propulsive. creating lift by pushing your body higher in the water seems to be a lot of energy that could have been spend trying to move it closer to the finish line rather than the clouds, and you are going to lose all of that momentum after the stroke when you sink right back down to the depth the sculling swimmer stays at; actually you will probably sink a little deeper due to the momentum.

I think you're right about there are a lot of misleading or odd statements in the article. It brings up a lot of interesting points but I don't think ultimately there's a lot of take-away for the triathlon swimmer looking to improve distance OWS.

The thing about a truly efficient S-shaped pull (Michael Phelps has a pretty exaggerated one but it fits in with his body position at each point) is that there actually should be very little diagonal. Many swimmers make the mistake of making the hand follow an S-shaped path (planing the hand). Instead, in a functional S-pull, the whole arm makes the S-shape BUT WITH THE HAND AND FOREARM ALWAYS PULLING BACK. This is very tricky to do especially when you put body rotation into the equation.

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Member

1748

Exton, PA

Subject: RE: Swim Stroke Analysis Results

You can straight arm pull if you want, but remember the basics of physics. Each action has an an equal and opposite reaction.

When you straight arm pull you spend 1/2 of your effort propelling forward, 1/4 of your effort pushing you up and 1/4 of your effort pushing you down.

I'll keep my S shape pull and you can try to catch me on the bike and run.

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Pro

5361

Subject: RE: Swim Stroke Analysis Results

here's my favorite video when people (like me) start talking about what a perfect stroke looks like:

http://www.youtube.com/watch?v=4YrZXqBKwuc

It's Janet Evans setting a new olympic record in the 800 back in 1988. She crushes some east german chick that looks twice her size.

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Melon Presser

52116

Subject: RE: Swim Stroke Analysis Results

morey000 - 2012-07-07 12:26 AM

here's my favorite video when people (like me) start talking about what a perfect stroke looks like:

http://www.youtube.com/watch?v=4YrZXqBKwuc

It's Janet Evans setting a new olympic record in the 800 back in 1988. She crushes some east german chick that looks twice her size.

The key is looking at what her stroke looks like UNDER the water. If there's anything Janet Evans and a whole host of neoprene-clad OWS triathletes have taught us, it's that how your arms re-load to do the next pull is not particularly relevant.

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Expert

2547

The Woodlands, TX

Subject: RE: Swim Stroke Analysis Results

Clempson - 2012-07-06 10:57 AM

i think the article is very misleading.

the article states that the study was done using the assumption that lift is important to an efficient stroke. is it, or is natural straight body position better? lift, as in getting your body up higher, forces fluid to divert under you; like an airplane wing does. obviously a straight arm stroke will do this naturally more than s-shaped stroke. the first third of the stroke is wasted pushing your arm down, and pushing your body up; the s-shape stroke focuses on attempting to divert as much of your energy towards pulling water back throughout the entire stroke; due to the s-shape nature though there is a little bit of diagonal force applied, which is why i think some swimmers have problems swimming straight, myself included.

"The better choice for human propulsion, he says, was the paddlelike deep-catch stroke, which actually produced more lift than sculling, along with a hefty dose of drag."

the article also doesn't seem to understand drag. it states that the deeper pull creates more, and that's good. this obviously is not the real world case, as drag is an impeding force, not propulsive. creating lift by pushing your body higher in the water seems to be a lot of energy that could have been spend trying to move it closer to the finish line rather than the clouds, and you are going to lose all of that momentum after the stroke when you sink right back down to the depth the sculling swimmer stays at; actually you will probably sink a little deeper due to the momentum.

I think you're looking at drag wrong. I few years ago it took me like 3 tries to read something and get my head around a certain drag explanation. The hand stays put. So drag is to be maximized. The more drag the more the hand is stationary and the more your body moves forward.

Also, like many things discussed on the internet, they (or we) are isolating a single event in a stroke. Even the scientist fessed up and said that the arm needed to be detached from the body for his results to ring true. How do you get a deep pull? by rotating your shoulders. How do you rotate your shoulders? a combo of kicking and shifting the way you pull. There's lots of reasons the best swimmers don't use "equal and opposite" the way it's being defined here. Because there are about 30 opposites that swimmers are trying to equal. Airplanes use flaps, we use hands. Look at that video of phelps again and notice all the changes in the pitch of his hand right after entry. That's not an accident.

I don't want to sound like some holistic hippie in a meadow, but you need to understand the stroke in its entirety to swim it right. Hopping in the water and just pulling straight back will leave your stoke a mess and your shoulders needing ice.

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Coach

9167

Stairway to Seven

Subject: RE: Swim Stroke Analysis Results

Clempson - 2012-07-06 9:57 AM

i think the article is very misleading.

the article states that the study was done using the assumption that lift is important to an efficient stroke. is it, or is natural straight body position better? lift, as in getting your body up higher, forces fluid to divert under you; like an airplane wing does. obviously a straight arm stroke will do this naturally more than s-shaped stroke. the first third of the stroke is wasted pushing your arm down, and pushing your body up; the s-shape stroke focuses on attempting to divert as much of your energy towards pulling water back throughout the entire stroke; due to the s-shape nature though there is a little bit of diagonal force applied, which is why i think some swimmers have problems swimming straight, myself included.

"The better choice for human propulsion, he says, was the paddlelike deep-catch stroke, which actually produced more lift than sculling, along with a hefty dose of drag."

the article also doesn't seem to understand drag. it states that the deeper pull creates more, and that's good. this obviously is not the real world case, as drag is an impeding force, not propulsive. creating lift by pushing your body higher in the water seems to be a lot of energy that could have been spend trying to move it closer to the finish line rather than the clouds, and you are going to lose all of that momentum after the stroke when you sink right back down to the depth the sculling swimmer stays at; actually you will probably sink a little deeper due to the momentum.

The problem is with the terminology. in propulsion research they talk about lift propulsion and drag propulsion. Imagine an airplane wing...when it moves forward with enough speed, lift is created moving it upwards. now take that wing and place it vertically in the water as if it were your hand sculling sidewas (or foot). With enough SIDEWAYS movement the theory is that the LIFT produced would move your body forward.

This is the classic debate that's been going on since the days of Doc Counsilman, and the consensus is that lift propulsion (moving you forward, not up toward the surface) is so minimal or even non-existent that it's negligible.

DRAG propulsion is the idea that you place a big old paddle in the water...your hand & forearm, and it creates drag relative to your body moving forward. In other words the forward movement is created due to the fact that your big old arm DOES create drag.

So that's the LIFT vs DRAG debate which is decades old and all evidence leans heavily in favor of DRAG propulsion being the only important component to be worried about.

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9167

Stairway to Seven

Subject: RE: Swim Stroke Analysis Results

tjfry - 2012-07-06 10:45 AM

I don't want to sound like some holistic hippie in a meadow, but you need to understand the stroke in its entirety to swim it right. Hopping in the water and just pulling straight back will leave your stoke a mess and your shoulders needing ice.

Face it...you are a holistic hippie and we all know it.

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Expert

2192

Greenville, SC

Subject: RE: Swim Stroke Analysis Results

ah ok, so drag in swimming is different from the rest of the world. working in the aero world im used to it being the resistive force of the fluid acting on the moving body, impeding movement in the direction you want to go, not as a propulsive force.

AdventureBear - 2012-07-06 1:33 PM

Imagine an airplane wing...when it moves forward with enough speed, lift is created moving it upwards. now take that wing and place it vertically in the water as if it were your hand sculling sidewas (or foot). With enough SIDEWAYS movement the theory is that the LIFT produced would move your body forward.

the direction of fluid flow is completely different over a wing vs your arm, so the fluid dynamic principles have to be completely different. if they worked the same people would swim left and right, not forwards.

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Member

297

Ann Arbor

Subject: RE: Swim Stroke Analysis Results

AdventureBear - 2012-07-06 1:33 PM

Clempson - 2012-07-06 9:57 AM

i think the article is very misleading.

the article states that the study was done using the assumption that lift is important to an efficient stroke. is it, or is natural straight body position better? lift, as in getting your body up higher, forces fluid to divert under you; like an airplane wing does. obviously a straight arm stroke will do this naturally more than s-shaped stroke. the first third of the stroke is wasted pushing your arm down, and pushing your body up; the s-shape stroke focuses on attempting to divert as much of your energy towards pulling water back throughout the entire stroke; due to the s-shape nature though there is a little bit of diagonal force applied, which is why i think some swimmers have problems swimming straight, myself included.

"The better choice for human propulsion, he says, was the paddlelike deep-catch stroke, which actually produced more lift than sculling, along with a hefty dose of drag."

the article also doesn't seem to understand drag. it states that the deeper pull creates more, and that's good. this obviously is not the real world case, as drag is an impeding force, not propulsive. creating lift by pushing your body higher in the water seems to be a lot of energy that could have been spend trying to move it closer to the finish line rather than the clouds, and you are going to lose all of that momentum after the stroke when you sink right back down to the depth the sculling swimmer stays at; actually you will probably sink a little deeper due to the momentum.

The problem is with the terminology. in propulsion research they talk about lift propulsion and drag propulsion. Imagine an airplane wing...when it moves forward with enough speed, lift is created moving it upwards. now take that wing and place it vertically in the water as if it were your hand sculling sidewas (or foot). With enough SIDEWAYS movement the theory is that the LIFT produced would move your body forward. This is the classic debate that's been going on since the days of Doc Counsilman, and the consensus is that lift propulsion (moving you forward, not up toward the surface) is so minimal or even non-existent that it's negligible. DRAG propulsion is the idea that you place a big old paddle in the water...your hand & forearm, and it creates drag relative to your body moving forward. In other words the forward movement is created due to the fact that your big old arm DOES create drag. So that's the LIFT vs DRAG debate which is decades old and all evidence leans heavily in favor of DRAG propulsion being the only important component to be worried about.

One person understood the article.

However, I cannot dismiss the whole Doc Counsilman angle... when my swimmer's "catch" the water, they seem to be doing some "lift" type forces so that their hand/arm is "stuck" in the water... but then again, they tend to do it in a straight line and there's a lot of simple drag and push going on.

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Veteran

393

Subject: RE: Swim Stroke Analysis Results

tjfry - 2012-07-06 9:14 AM

morey000 - 2012-07-05 9:01 PM

OK- here it is. A straight, deep catch is a more efficient stroke than the s-shaped pull that I learned when I was in high school.

the little caveat to this is- you need to have some pretty well developed shoulder strength to make it work.

enjoy-

http://well.blogs.nytimes.com/2012/07/04/delineating-the-perfect-swim-stroke/?ref=health

Yep. Now all we have to do is detach our body so that no other part of freestyle comes into play.

Oh, and someone needs to tell this guy he's been doing it wrong:

http://youtu.be/SuRLkXB2IBE

Phelps obviously doesn't know what he's doing, but his dinner-plate hands save him from himself.

Coach

9167

Stairway to Seven

Subject: RE: Swim Stroke Analysis Results

Clempson - 2012-07-06 12:10 PM

the direction of fluid flow is completely different over a wing vs your arm, so the fluid dynamic principles have to be completely different. if they worked the same people would swim left and right, not forwards.

Of course it is, that's why it's so difficult to study. But the sculling is the sideways movement of say, a hand, with a convex-ish shape, moving sideaways thorugh the water (relative to the swimmer, right to left or left to right) therefore the supposed flow that results creates propulsion in the forward direction (relative to the swimmer), not left & right.

I'm not saying that this is what happens in real life, but this is the proposed mechanism and is a HUGE matter in the 'debate' of propulsion in swimming. I put 'debate' in quotes because most of the studies that have come out suggest that actual lift propulsion is non-existent or minimal in magnitude compared to drag propulsion. But it's extremely difficult to study because of the shape of the arm and the dynamic, spiraling flow of the fluild along the surface of the arm as it moves in any direction.

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9167

Stairway to Seven

Subject: RE: Swim Stroke Analysis Results

mike761 - 2012-07-06 10:26 AM

You can straight arm pull if you want, but remember the basics of physics. Each action has an an equal and opposite reaction.

When you straight arm pull you spend 1/2 of your effort propelling forward, 1/4 of your effort pushing you up and 1/4 of your effort pushing you down.

I'll keep my S shape pull and you can try to catch me on the bike and run.

Deep catch (according to the article) is not the same as a straight pull. It has more to do with the lack of side to side movement, and the initial angle of attack upon entry.

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Elite

7783

PEI, Canada

Subject: RE: Swim Stroke Analysis Results

AdventureBear - 2012-07-07 1:16 AM

Clempson - 2012-07-06 12:10 PM

the direction of fluid flow is completely different over a wing vs your arm, so the fluid dynamic principles have to be completely different. if they worked the same people would swim left and right, not forwards.

Of course it is, that's why it's so difficult to study. But the sculling is the sideways movement of say, a hand, with a convex-ish shape, moving sideaways thorugh the water (relative to the swimmer, right to left or left to right) therefore the supposed flow that results creates propulsion in the forward direction (relative to the swimmer), not left & right. I'm not saying that this is what happens in real life, but this is the proposed mechanism and is a HUGE matter in the 'debate' of propulsion in swimming. I put 'debate' in quotes because most of the studies that have come out suggest that actual lift propulsion is non-existent or minimal in magnitude compared to drag propulsion. But it's extremely difficult to study because of the shape of the arm and the dynamic, spiraling flow of the fluild along the surface of the arm as it moves in any direction.

I'm far from an engineer but I did live in an apartment for one year of university with two guys that cursed their fluids courses constantly so I think that makes me qualified....

It seems to me that the shape of the airfoil on an airplane's wing is so sensitive to changes that it would be impossible to generate any real "lift" with a hand and arm in water. Think about how a small amount of ice buildup can dramatically reduce the lift it produces - hence deicing prior to take off.

*disclaimer* - the above is based on no science whatsoever!

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9167

Stairway to Seven

Subject: RE: Swim Stroke Analysis Results

axteraa - 2012-07-07 5:02 AM

It seems to me that the shape of the airfoil on an airplane's wing is so sensitive to changes that it would be impossible to generate any real "lift" with a hand and arm in water. Think about how a small amount of ice buildup can dramatically reduce the lift it produces - hence deicing prior to take off.

*disclaimer* - the above is based on no science whatsoever!

Exactly! But that's was the original proposed mechanism behind the S-pull. It was observed (by Councilman watching Spitz underwater video I believe) and explained as lift producing. In reality Spitz was not trying to swim that way deliberately and some of the pull shape was due to body rotation as the hand passed the body. Some may be bio-mechanical in that it's a little less stressful to reposition the hand/forearm complex, OR the swimmer may be seeking out "still" water.

But the S-pull has subsequently been taught for years and I'm sure Rod Havrulak would agree that it's a great disservice to swimmers everywhere.

That's not to say that Phelps for example doesn't have an efficient pull...but when you have the intention of creating an "S" shape in the water to mimic what was observed (in Spitz for example), there is a big, big, big risk of wasting movement in the water and giving up propulsion.

Cecil Colwin's book has some of the best discussion on what "natural" or "elite" swimmers seem to be doing without a lot of instruction. Likely swimmers with atypical or inefficient appearing strokes to coaches (Evans' recovery, Phelps traditional S-shape, Weissmuller's heads up swimming) were naturally able to sense their interaction with the water and create effective forward movement. Couple that with big engines in terms of threshold/Vo2 max, opportunity to practice in a coached environment and the motivation to put the work in and you've got champions. Take away any one of those elements...even if the stroke is "perfect" and you'll probably not be swimming at Olympic Trials.

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Swim Stroke Analysis Results

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