Interestingly, many differences become apparent if you have an opportunity to watch inline skaters of a variety of skill levels.

	* People new to the sport initially try to walk on their skates, with very little success (the novice technique). Walking requires that when you push back on the ground, it must push back on you, and this no longer happens when there are wheels on your feet.

	* After a while, recreational skaters realize that they can make themselves go forward without a lot of effort by angling their feet outward at the toes and shifting their weight from one foot to the other. The vast majority of inline skaters use this technique (the recreational technique).

	* A new level of propulsion efficiency happens when a skater loses their fear of the sensation of falling. They can do the above technique but will wait on each foot as their body falls inwards before catching themselves with the other foot and repeating the procedure on the other side. Now, they are able to use most of their body weight as an inverted pendulum with greatly increased speed and reduced effort. Olympic ice speedskaters have refined this technique to a very fine degree (classic speedskating technique).

	* Professional inline skaters utilize a fourth technique (the double-push), where instead of always falling inwards, they set a skate down in front of and across their body and fall over it outwards before sweeping the skate back under their body to stop their fall and using it as in the classic speedskating technique to fall inwards, then repeating the fall-outwards/fall-inwards sequence with the other foot. This technique is not possible on fixed ice blades since the blades grip too solidly to do the sweep-across movement. The sensation of falling outwards over one foot instinctively tells your body that a crash is imminent, making mastery of this last technique require a complete relearning of this aspect of kinesthetic sense. To the typical recreational skater, the double-push looks very bizarre, but it is so efficient a method of inline propulsion that it is impossible for even the very strongest skater using the recreational technique to keep up.  

SpeedSkating illustrates that sometimes, in order to progress, it is not sufficient to keep getting better and stronger at what you were already doing; rather, it is sometimes required that you unlearn what you know, and temporarily sacrifice performance while you reinvent your methodologies for long-term benefit.

Here's what the double-push looks like -
http://www.breakawayskate.com/skate/dp/publowdpani.gif

And here's the physics - http://home1.gte.net/pjbemail/pushpull.html.

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Contributors:  AndyPierce, MichaelSchuerig
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''rather, it is sometimes required that you unlearn what you know, and temporarily sacrifice performance while you reinvent your methodologies''

Is it as clear-cut as that? Is it not possible to progress from recreational technique via practicing cornering - improving balance and familiarity with the falling sensation, but not falling? Are you really 'unlearning'? The thought behind these questions is that apparently discontinuous evolutionary change often makes a lot more sense once you know the intermediate steps too - or the hidden variables behind the change.

I can't say how good my double-push technique is, but for me it was a gradual change. Nothing nasty or unpleasant - just ''Hey, this is faster''. Beginning skaters usually set down their feet well outwards. As you get better, you set down your feet ever more inward as this gives you a longer way to push to the outside. The next step, in my experience, is to then start pulling inwards before pushing outwards. -- MS

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This story is made more fantastic when one realizes that the learning is ultimately expressed by a neural gait generator that evolved before the wheel. Here is a ScientificAmerican article that discusses this class of neural circuit. 
	* http://www.cureparalysis.org/nnvl/ [this link is down, is the article still available somewhere else?]

''Not elsewhere online, except archived at http://web.archive.org/web/20000919073348/http://www.cureparalysis.org/nnvl/''
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This is related to PracticeMakesPermanent.

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CategoryEducation