While watching the swimming tournament at the London Summer Olympics, take a good look at the hands of the competitive swimmers! For, new research finds that this hand position creates an “invisible web” of water that gives swimmers more speed. Now, should Michael Phelps improve his ‘finger-techniques’?

Researcher Adrian Bejan, a professor of mechanical engineering at Duke University reports:

“It is a counterintuitive idea, the fact that you should paddle with a fork, not with an oar.”

However, the 2012 study was preceeded by a 2009 study which had already pointed out why most swimmers spread their fingers while swimming (see the picture below – describing how water flow varies for different finger positions).

Webbed feet and hands, of course, are a common trait of swimming animals from frogs to whales. In human swimmers, the invisible web of water allows them not to propel themselves faster, but to better lift themselves out of the water. That’s where the speed comes from, Bejan said. Swimmers push against the water’s surface not unlike South American Lizards, which can scamper on top of water by slapping their big feet against the surface. This force propels the swimmers out of the water, where they then fall forward, generating a horizontal wave.

“The higher you are above the water, the faster you fall forward and you see this effect in greater speed,” Bejan said.

With ideal finger spacing, the forces a swimmer can exert are 53 percent greater than those produced with no finger spacing, Bejan and his colleagues reported online June 9 in the Journal of Theoretical Biology. For aspiring swimmers at home, the perfect spacing is between 0.2 and 0.4 times the diameter of the finger itself.

The findings could have implications for better swimming robots and propulsion systems, Bejan said. They’re also handy for those trying to beat personal bests in the water.

What do you think: should Michael Phelps improve his finger-swimming techniques… in order to make another golden- paddle?

(Check out Phelps’ finger techniques below!)

Advertisements

A new study revealed how hand shape can be identified via measurements on 3 hand dimensions, including: finger length, palm width & palm length.

The study points out that each of the so-called ‘elemental hand shapes’ (earth hand shape, fire hand shape, air hand shape, and water hand shape) can be recognized by it’s proportions relative to each other.

The picture above demonstrates how your hand shape can be identified via the ‘hand shape profile’ – which concerns a code with three elements involved, where the combination reveals the (elemental) hand shape type.


More details are discussed in the article: 

Finger length proportions & elemental hand shapes!

The TOP 10 most irritating HAND GESTURES resulted from an American study including 2,000 people – and was commissioned to mark the launch of iPhone app Goggle Eyes.

1. Inverted commas
2. Talk to the hand
3. None of your business
4. Blah blah blah
5. The pistol
6. Hand punching
7. I’m watching you
8. Call me
9. Fake yawn
10. Cutthroat

Read more at DailyMail.co.uk

The finger-flicking ‘inverted commas’ motion has been hailed as the most irritating hand gesture.

‘Talk to the hand!’ was voted the second most annoying gesture.

‘None of your buisiness’ (nosetapping) was voted the third most annoying gesture.

‘Blah blah blah’ (making an imaginary mouth with the hand) is the fourth most annoying thing to do when talking with people.

Firing an imaginary pistol was voted fifth most galling of all hand signals.

Discover more about the meaning of hand gestures at Hand Gestures News

Have you ever tried to visualize your hands… after closing your eyes? Previous studies had shown that we tend to underestimate our finger length increasingly from thumb to little finger. Researchers at Birkbeck, University of London,  made a new discovery after examing a 38-year-old woman born without a left arm. Your brains do not require visual or sensory input to represent your hands!

New Scientist reports:

For the first time, the perceived shape of a phantom limb has been measured. This should make it possible to learn more about how the brain represents what we look like.

The illusion of a phantom limb can kick in after an amputation or in people missing limbs from congenital disease. The result is the sensation that the limb is, in fact, present.

One theory suggests people with phantom limbs take cues from those around them to work out what their missing body part looks like. Another theory is that the sensation of an invisible limb reflects brain activity in regions that map our body in space.

To clarify the sensory origins of phantom limbs, Matthew Longo at Birkbeck, University of London, and colleagues enlisted the help of CL – a 38-year-old woman born without a left arm, who periodically feels she has a phantom hand. They asked her to place her right hand beneath a board and indicate where she believed her fingertips and knuckles were. She then repeated the exercise imagining that her phantom left hand was beneath the board instead.

Previous studies have shown that we tend to underestimate our finger length increasingly from thumb to little finger. This mirrors differences in the sensitivity and size of areas in the brain’s  somatosensory cortex that are thought to represent each digit, probably by making use of visual, mechanical and tactile feedback. The thumb is represented by a larger area of the cortex than the little finger.

As expected, CL reported these characteristic distortions when indicating the dimensions of her right hand. But she made the same errors when describing her phantom hand, implying she perceives both hands in the same way (Clinical Psychological Science).

That suggests there is “some structural representation in the brain of a body part that has never existed”, says Patrick Haggard at University College London, another member of the team. This implies that the somatosensory cortex does not require visual or sensory input to represent a body structure.

Understanding how the brain perceives the body could have broader implications. Longo says there are a few studies showing that people with eating disorders may inaccurately judge the size of their body from tactile feedback. Those results suggest there may be some relation between somatosensory representations of the body and our conscious feelings of what our body is like,” he says.

Read more about previous research that demonstrated through hand projections how faulty body perceptions work in  anorexia and other eating discorders:

Hand projections demonstrate how anorexia works 

Here’s a fun experiment: stop what you’re doing and use your hands to count to ten. Done? Good. Now remember how you did it, because we’re about to analyze your technique; as it turns out, how you count with your hands may say a lot more about you than you think.

So, how do you count?

Many cultures use some variation of what psychologists call the “closed fist method”, wherein one starts with a closed fist, and begins counting by unfurling the fingers of his or her hand. But the similarities end there.

“The degree of cultural diversity in finger counting… has been grossly underestimated,” write psychologists Andrea Bender and Sieghard Beller in the latest issue of  Cognition.

FULL ARTICLE:

What finger-counting says about you and your brain