CATCH-UP STROKING SHOULD BE CONSIDERED A TECHNIQUE ERROR
Schnitzle, C., Seifert, L., Ernwein, V., & Chollet, D. (2008). Arm coordination adaptations assessment in swimming. International Journal of Sports Medicine, 29, 480-487.
The link between modifications in arm coordination (ldC) and intracyclic velocity variation (IVV) as a function of swim pace and gender was investigated. Elite swimmers (N = 12) performed five different swim paces. Video analysis allowed arm coordination determination. The intracyclic velocity variation was determined with a velocity-meter system.
There was a significant increase in arm coordination with swim pace but no significant change in intracyclic velocity variation. There was a gender effect for the mean values of both arm coordination and intracyclic velocity variation. This suggests that the increase in arm coordination with swimming velocity helps to maintain intracyclic velocity stability, and the mean arm coordination and the intracyclic velocity variation level are determined by the relationship between anthropometric parameters and mechanical power output. Indeed, compared to males, the females generally had a lower mechanical power output, and lower drag to overcome, which explains the lower intracyclic velocity variation found. It was concluded that increasing arm coordination could be a strategy adopted by elite swimmers to maintain intracyclic velocity variation at a constant level, despite increases in both propulsive and drag forces and in relation to individual characteristics. Thus, the intracyclic velocity variation-arm coordination relationship may be an interesting tool to determine a swimmer's misadaptation to the swim pace and to orient individual coaching in coordination analysis.
Implication. Arm coordination refers to the degree to which the alternating arms function opposite each other, reducing any intertial lag between the finish of one and the start of propulsion of the other. As swimmers go faster, those lags, which are usually evidence of a degree of "catch-up stroke", shorten. Females perform less catch-up stroking than males. Thus, the magnitude of intracyclic velocity variation, that is, the difference between the peak and lowest forward velocities in a swimming stroke cycle, should be considered a diagnostic index of stroking technique error.
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