To evaluate a swimmer's style, an efficient practitioner relies on his observations of the swimmer's movement and his ability to judge other physical capacities of the swimmer. When his observation is, however, aided by objective film data and when he has adequate instrumentation to measure specific anthropometric, motor, and physiological parameters, the effectiveness of his evaluation should be increased. The key to this evaluation is not only the establishment of factors governing proper swimming techniques (e.g., synchronization, flexibility, etc.) but obtaining and, most important, applying relevant measurements (Hochmuth, 1967; Miller and Nelson, 1973). In swimming, the lack of visibility of the movement remains a particular problem for both researcher and practitioner; as a result, nterpretations of the hydromechanical aspects of the movement are still a source of controversy. Because of this situation, some specific temporal and spatial data have been coHected from films of world-class swimmers. Methods were developed at the same time to present this information on one graph. From this study, reported earlier, some hypotheses regarding "optimal" stroke mechanics have been formed. With few exceptions, such as the backstroker Stamm (see later), champion swimmers use uniform patterns as compared with intermediate swimmers. NaturaHy, the hypotheses developed needed confirmation through further research. With this in mind, in the following work, good swimmers simulated (while being filmed) some correct and incorrect movements or positions (e.g., no roll, extreme inclinations of the trunk, exaggerated sideways movements of the hips, etc.). With the insights gained from this work and the information gained from the champions' patterns, the testing of the validity of an evaluatior procedure for swimmers was started (Persyn, 1974; Persyn, De Maeyer, and Vervaecke, 1975; Persyn and Vervaecke, 1975 a, b; Persyn, Vervaecke, and Verhetsel, 1976). First, the patterns of 18 swimmers of the National Belgian Team were studied, using videotape, but their physical capacities were controlled only roughly (Persyn, Thewissen, and Vervaecke, 1976). Later we were fortunate to have a group of seven young swimmers (12-14 years old), coached by a postgraduate specialist. These young swimmers had been trained in a wide range of skill variations, increasing greatly the ease of correction. The cooperation and patience of these subjects and their coach were very helpful in controlling the correction process.
© Copyright 1979 Swimming III. Proceedings of the Third International Symposium of Biomechanics in Swimming, University of Alberta, Edmonton, Canada. Published by University Park Press. All rights reserved.