Musculoskeletal simulation of swimming using motion capture data

Abstract

There are many studies about swimming by kinematic and partial kinetic analysis. In order to obtain muscle activity during swimming, the experiments using the electromyogram were conducted as well. However, measurable muscles are limited in this experiment. And there are few musculoskeletal analysis of swimming, since it is difficult to compute the fluid force acting on the whole body of a swimmer. The objectives of this study were to construct the method of musculoskeletal simulation from swimming motion capture data, and analyze muscle activity. First, swimming motion capture data was transformed into body geometry data and swimming motion (absolute angles of segments) of SWUM using Blender. In SWUM, fluid forces of each segments were calculated. Then, swimming motion of SWUM was transformed into joints angles of AnyBody Modeling System using MATLAB. Finally, muscle activity of the whole body was calculated using AnyBody inputting the swimming motion and fluid forces. From the example of breaststroke, it was found that all transformations except for 2 DOF joints were conducted successfully.