title: The optimum finger spacing in human swimming.
abstract: Competitive swimmers spread fingers during the propulsive stroke. Due to the inherent inefficiency of human swimming, the question is: does this strategy enhance performance or is it just a more comfortable hand posture? Here we show, through computational fluid dynamics (CFD) of a 3D model of the hand, that an optimal finger spacing (12 degrees , roughly corresponding to the resting hand posture) increases the drag coefficient (+8.8%), which is 'functionally equivalent' to a greater hand palm area, thus a lower stroke frequency can produce the same thrust, with benefits to muscle, hydraulic and propulsive efficiencies. CFD, through flow visualization, provides an explanation for the increased drag associated with the optimum finger spacing.
authors: Department of Human Physiology, Faculty of Medicine, University of Milano, 20133 Milano, Italy. alberto.minetti@unimi.it
authors: Alberto E
authors: AE
authors: Minetti
authors: Georgios
authors: G
authors: Machtsiras
authors: Jonathan C
authors: JC
authors: Masters
mesh_terms: D003198:Computer Simulation; D005385:Fingers / Q000033:anatomy & histology / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D005082:Physical Exertion / Q000502:physiology*; D012212:Rheology / Q000379:methods*; D013550:Swimming / Q000502:physiology*; D013647:Task Performance and Analysis