The position of the fingers and toes is seldom discussed on pool decks. Literature suggests a slight spread of the fingers maximizes propulsion. Moreover, the amount of spread is proportional to the speed of the moving object.
However, there is a debate if a larger paddle exerts more force on the surrounding water, leading to less efficient swimming.
This study looked to see if the spacing between the hands and feet was efficient, and what is the optimal distance if this spread was efficient.
What was done
The researchers took cylinders and placed and had a constant stream against the cylinders. These researchers performed trials with 2 – 4 cylinders.
Results
It was found spacing the cylinders increased the amount of force produced. The amount force increased greatly with a higher number of cylinders. It was suggested the optimal spacing depends solely on the diameter of the two adjacent cylinders.
In the Reynolds range of 20 – 100, the researchers found that the optimal spacing is in the range of 0.2D – 0.4 of the diameter of the cylinder, and decreases slowly as Re increases.
Discussion
This paper suggests spacing the fingers and toes is optimal for force production. More importantly, there is an optimal spacing that maximizes force production.
Practical Implication
This study confirms the notion of spreading the fingers. Not many studies known to this author have discussed or researched toe spreading in humans, likely as this ability is difficult and many studies suggest the legs minimally produce force in human swimming.
Reference:
- Lorente S, Cetkin E, Bello-Ochende T, Meyer JP, Bejan A. The constructual-law physics of
why swimmers must spread their fingers and toes. J Theor Biol. 2012 Jun 9. [Epub ahead of
print]
Comments 3
For years, I have taught my swimmers to hold their fingers in a relaxed position – having the fingers just slightly apart. I don’t want them to hold the fingers together or create spiderman fingers. You can actually feel the strain on the muscles unless the fingers are relaxed. This leads to energy conversation in the forearms, allowing the swimmer to go the extra distance.
The Science Of Swimming
by James E. Counsilman
1967
Mentioned spread of fingers. If I remember correctly his research came up with a slightly spaced arrangement.
You do remember correctly. My coach studied councilman and TSOS and taught some degree of finger splay from that time.