The purpose of this study was to investigate the validity of the force measurement in tethered swimming (TS) in place for the power measurement in semi-tethered swimming (STS). To perform this purpose, force in TS of primary school swimmers, as subjects, participated in N prefecture swimming association official swimming competition as a field test was measured using the electrical force gauge (IMADA: DPX-50T). Furthermore, the swimming velocity as a performance in each subject was calculated from the record in 50m. The relationship between the force in TS and the swimming velocity was investigated. Additionally, to reconfirm the relationship the force in TS and the performance in swimmers, the force of TS of 10 male primary and junior high school swimmers were measured using the above mentioned force gauge and analysis system (ELMEC: DAQ-WIN Ver4.7) as a laboratory test. In this measurement, the above-mentioned relationship was re-examined.
The results of this study were summarized as follows;
1) The relationships between the force in TS (Y) and the swimming velocity (X) in male crawl stroke in the field test was Y=14.42X-8.63 (R=0.58). This relationship was significant statistically (p<0.001).
2) The relationships between the force in TS and the swimming velocity in male crawl strake in the laboratory test was Y=35.21X-33.22 (R=0.94). This relationship was significant statistically (pく0.001).
3) From these results, the force measurement in TS was able to use in place for the power measurement in semi-tethered swimming (STS) as an index of the performance of swimmer.
