Optimising the freestyle swimming stroke: the effect of finger spread

Previous studies of optimal swimming technique have had limited success simulating the complex motion of a swimming stroke, either experimentally or through computer modelling. This study experimentally simulated the dynamics of the freestyle stroke in the pull-down phase by measuring the propulsive force created by two models of human hands: one with fingers held together and the other held with fingers spread at 10∘. The stroke motion was created by towing the model through a tank of water while simultaneously using a two-axis motor assembly to create a sculling motion. In the testing of the models, the maximum sculling pitch angle was varied from 20∘ to 50∘. It was determined with 95% confidence that a finger spread of 10∘ creates more stroke force than a fingers-together configuration across all pitch angles tested.