Swimming on the web

Fingers together or slightly separated?

Two scientific studies have addressed the question of whether it is better to keep one's fingers together while pulling, or allow slight separation.  One study used computational fluid dynamics:

http://www.springerlink.com/content/j3m844150606v846/

The other study tested with a mechanical model which was dragged through the water:

http://www.posetech.com/FORUM/finger_spacing.pdf

Both studies found that optimum separation is around 10-12 degrees, or about 8mm apart, about the amount the fingers separate naturally when relaxed.

A slight complication is that the CFD approach shows a non-linear relationship with minimum propulsive force being generated with the fingers separated by 4.4mm.  This sensitivity, 3mm is good, 4.4mm is bad, 8mm is best, raises the question of how precisely swimmers can control their finger separation.  The tests also appear to have tested just the hand area, the 8.8% improvement found by the CFD study would likely be lower if the forearm had been included.

Posted at 02:11PM Feb 15, 2010 by Lindsay in General  |  Comments[0]