London - It may be hard to swallow for amateur swimmers, but keeping your fingers firmly together to create a oar-style effect is not the best technique.
Instead, counter-intuitive as it seems, keeping the fingers slightly apart like a fork apparently makes a swimmer faster.
A study claims that an ‘invisible web’ of water is created by spread fingers, allowing swimmers to propel themselves with more force – and that the technique is already used by the professionals.
‘It is a counter-intuitive idea, the fact that you should paddle with a fork, not with an oar,’ said researcher Adrian Bejan, a professor of mechanical engineering at Duke University in Durham, North Carolina.
The reason is that when a solid object moves through a fluid, the layer of fluid that touches the surface ‘sticks’ and gets dragged along with the object. When swimmers spread their fingers just right, each individual digit forms its own layer.
With ideal finger spacing, the forces a swimmer can exert in this way are 53 percent greater than those produced with no finger spacing, according to the study in the Journal of Theoretical Biology. The perfect spacing is between 20 percent and 40 percent of the diameter of the finger.
This allows swimmers to lift themselves more easily out of the water, where resistance is lower, resulting in increased speed.
Mr Bejan added that the findings could also have implications for the development of better automated propulsion systems. - Daily Mail