I heard that TI is based on the research of a Russian scientist. Is this true? Who was it? Any published papers or data?
Thanks.
Former Member
but (some/most/all?) engineers just don't roll like that.
I like that.
There are other reasons, of course. One could be reduced to a simple question:
How do you know that what you are being told is true?
In my years in martial arts I have had some really fantastic teachers. Some of the best knew as much about physics as I know about underwater basket-weaving. While most of what they said, did or taught was on the money, every so often they'd say something that was clearly not rooted in reality.
Of course, you listen and move on. You have to show respect for who they are. However, without an understanding of some of the fundamental physics and bio-mechanics other students might just think that what they are been told is, in fact, true.
I've seen a trick performed at dojos that eventually made it into a commercial to sell you a "magical" bracelet. I'm sure you've seen it: A guy grabs an old lady by the arm and pulls. She quickly looses her balance. They she puts on this $20 bracelet. The guy grabs and pulls again and the woman stays in place, aided by the magical powers of the bracelet. I've seen this done with four people pulling on the demonstrators arms.
Well, if you understand vector decomposition --the way forces distribute themselves based on how they are applied-- it is very easy to understand how to do the trick. And of course, you also understand that there is no such magic.
This is an extreme example to simply illustrate that it is sometimes useful to truly understand why one is doing what one is doing.
For example, I find myself questioning the very first instants of a "traditional" catch. The hand touches the surface of the water and you start to apply power. For simplicity, let's assume that you don't bend your hand at the wrist. Well, funny enough this is a vector decomposition issue. The force you apply to the water with your arm and palm will distribute itself based on some pretty well known principles. And so, at 15 degrees down from flat-and-level with the water surface only about 25% of the force you are applying is moving you forward. At 30% it goes up to 50% and at 45 degrees it's about 70%.
I look at that and can only think: "Applying any power in the first 25 to 30 degrees of motion is a complete waste of energy".
Well, funny enough, it seems that the TI folks are promoting the idea of inserting your arm in spear-like fashion into the water such that you start your catch or power stroke somewhere around 30 degrees down from the surface. On first inspection that makes a lot of sense to me. It would seem that you only really want to apply power from 30 to 30, meaning that you spear your arm into a position 30 degrees down from the surface at the start of the the stroke and the power stroke ends when your arm is 30 degrees from the surface on the back side. Looking at this oversimplification you could almost argue that 45 to 45 is the right range.
Of course, I am over-simplifying. There are hydrodynamic factors that might come into play (like generating some lift due to the forward velocity you carry) and modifying the shape of your arm to improve the way forces are developed. One example of that might be tilting your hand downward at the start of the catch and trying to keep your palm pointed backwards for the rest of the stroke.
Anyhow, some of the things that keep me up at night...
I like that.
For example, I find myself questioning the very first instants of a "traditional" catch.
Be careful in what you are calling traditional. Many salesmen will try to set themselves apart by saying that they are doing something totally different than anyone else. when in actuality some o the things they are speaking of is well accepted.
The idea that you are talking about, getting your forearm orthogonal to the direction of flow early and then really putting on the gas is promulgated in many places. The concept is often called early vertical forearm. It's a good idea, one which adult swimmers can get injured with or give up on due tot pain because they don't have the internal rotation at the shoulder to pull it off and make substitution motions instead and can end up hurt.
You'll also see it talked about as a significant elbow bend. This kind of accomplishes the same thing. Gets your forearm orthogonal to whee you want to go. Since there is not much internal rotation, the forearm isn't vertical.
Look around and you'll see that what you are calling a traditional catch is practiced in extremely fast swimming with some sprinters who like that style. Even so, they are pushing down and back from the get go, getting their hands into the orthogonal position as quickly as possible, understanding that their turnover is so fast, you won't see the big break at the elbow that you might see in middle distance or distance swimmers.
I once was told by a TI practitioner that the body roll was controlled by the action of the big toe. I also talked about this spearing action a few years ago. By spearing the water you probably break Newtons third law. I believe if you spear the water you actually will not be steamlined. This whole subject has been gone over so many times. Be a TI admirer if you wish but it was never anything I would want to try to emulate.
...My search isn't as much for the origins of TI as it is for a better understanding of the physics and bio-mechanics of swimming. Being an engineer I usually like to dig deeper into areas of interest to gain a better understanding.
Try a search like:
www.google.com/search
This link may be interesting to you:
Analysis of Grant Hackett's and Ian Thorpe's Swimming Technique
www.svl.ch/.../
And this one too:
Thoughts on the Crawl Stroke - By Marshall Adams
www.swimmingworldmagazine.com/.../200007-01st_art.asp
... which includes:
"The fact that Thorpe takes five-tenths of a second to accomplish this movement in a 1.5-second total stroke cycle demonstrates the importance of this positioning movement to the stroke." (Read the rest of that section to "get it".)
I'm just using Ian Thorpe as an example, feel free to use any high-profile swimmer in a search.
You could spend all day reading articles on the topic of stroke analysis... like:
Swimming Stroke Length, Stroke Rate and a Swimmer's Training
swimming.about.com/.../swimstrokerate.htm
Reading is great, so is asking questions and having discussions with coaches and swimmers... but... Mostly I just try to feel the water.
:-)
Be a TI admirer if you wish but it was never anything I would want to try to emulate.
careful george.... some of us still remember when you used to link to TI videos on your web site
I have looked at just about everything and have viewed just about everything. It does not mean I have to agree with everthing I have seen.
When a certain TI instructor looked at my stroke the reply was - You are more TI than TI.
careful george.... some of us still remember when you used to link to TI videos on your web site
There's another way to think of this, though. If you want a full extension out front your arm must go through some range of motion before reaching 30 degrees, so why waste that part of the stroke even if it is only contributing a small amount to forward propulsion? I think this is where a "sprint" stroke versus a "distance" stroke diverge somewhat. In a sprint your goal is to apply as much force as you can. This means a rapid turnover and getting as much from your pull as possible. In distance you have to start emphasizing efficiency over pure power and that's where your vector mechanics come into play more.
I can see that it makes sense to mind efficiency a lot more for distance than for sprints. One aspect that makes looking at this far more complex is bio-mechanics. The structure and musculature that move the arm have optimum force, speed and efficiency production ranges and these might not exactly coincide with what is best for swimming...we did not evolve to be the best at moving through water.
I look at that and can only think: "Applying any power in the first 25 to 30 degrees of motion is a complete waste of energy".
There's another way to think of this, though. If you want a full extension out front your arm must go through some range of motion before reaching 30 degrees, so why waste that part of the stroke even if it is only contributing a small amount to forward propulsion? I think this is where a "sprint" stroke versus a "distance" stroke diverge somewhat. In a sprint your goal is to apply as much force as you can. This means a rapid turnover and getting as much from your pull as possible. In distance you have to start emphasizing efficiency over pure power and that's where your vector mechanics come into play more.
By spearing the water you probably break Newtons third law. I believe if you spear the water you actually will not be steamlined.
I think I see what you're getting at. You aren't breaking Newton's Third Law, but you certainly are governed by it. "Spearing" your arm in will cause an equal and opposite reaction, so it's obviously going to slow you down. But the question is whether this additional drag is overcome by the increased forward propulsion your arm will then have in the power phase of the pull.
