A simple analytical model for the crawl stroke

Abstract A simple analytical model for the crawl stroke is described. The swimmer is modelled as a torso with arms rotating like paddle wheels; for simplicity the kick is ignored. Starting with theoretical and experimental estimates for drag coefficents and anatomical data from a male collegiate swimming team, the model was adjusted to fit certain tethered and free swimming data. Its behavior was then compared to that of real swimmers in five different experimental situations and good general agreement was observed. The model was found to require much lower drag forces than are measured experimentally, however, perhaps because the kick was not considered. The model provides insight into several aspects of swimming research, including the relationship between tethered swimming forces and actual propulsive forces during free swimming.