Recently the question of closed versus open fingers came up on the Facebook Swim Coaches group (what an incredible collection of coaching minds!), and it amazed me as to the diversity of opinion on what I thought was more or less a closed question. So I went looking to not only find out the present state of the research, but also to see what coaches and athletes were thinking. Here’s just a sampling.
Most said keep the fingers and thumb relaxed and in a natural position. The next theme involved variations on fingers tightly together so no water would ‘slip’ through. And many specified exact finger spacings or a small range of spacings. Here are some other comments from coaches.
- thumb should be at 90° with four tight fingers
- thumb anywhere but 90°
- cup your hand so that the water doesn’t ‘spill’ over the sides
- finger spacing should be with width of your fingers
- swimmers should wear finger spacing gloves to train the fingers
- (and my favourite) open fingers mean the palm of the hand will move through the water more quickly, so attention has to be paid to moving the fingers faster to catch up
The general idea is that a large number of swim sites discuss the issue but simplify the scientific study results horribly, resulting in incorrect generalizations and bad explanations. As a result, far too many professional coaches and swimmers are still confused about optimal finger spacing.
So let’s start with a basic understanding of the problem, and then we’ll get to the studies that have been done.
Most of the problems come from a misunderstanding of how fluid dynamics work. At the simplest level, there are 3 factors affecting the drag coefficient of the hand (roughly equating to the effective surface area of the hand).