For elite swimmers, the difference between first place and second place might not have much to do with spending those extra hours of training.
Recent research explores how a tiny change in your stroke can be a big deal.
A Netherlands-based team of researchers focused on how swimmers position their hands, or what they call the “hydrodynamics of a front crawl.”
The researchers tested the efficiency of swimmers who closed their fingers together and spread their fingers apart in varying degrees. After testing 3-D hand models in wind tunnels and fluid dynamics simulations, they concluded that swimmers who spread their fingers apart slightly have the highest swimming efficiency.
With spread fingers there is more drag against the water and, therefore, an increase in thrust. Spreading your fingers like this is called the “rake position.” In the rake position you can propel yourself forward without having to put as much power into your stroke.
TOP PANEL (A) shows varying degrees of finger openness, from 0 degrees to 20 degrees. Swimmers who open their hands 10 degrees have the greatest efficiency. MIDDLE RIGHT, PANEL (B), shows a rendering of the wind tunnel configuration. LOWER LEFT, PANEL (C) shows the computational domain in which force moments are computed with respect to point P.
The change is small, but doctoral student and researcher Josje van Houwelingen explained that for top swimmers it “can make the difference between a gold medal and no medal at all.”
While everyone might not be a top swimmer, the researchers said that they hope the study might “inspire other swimmers who are not Olympic-caliber to think about fluid dynamics, and contemplate the fluctuating forces which their hand and fingers experience while doing those boring laps.”