Hohmann, A., Fehr, U., & Fankel, J. (2010). Diagnosis of swimming technique by fully tethered swimming. A paper presented at the XIth International Symposium for Biomechanics and Medicine in Swimming, Oslo, June 16–19, 2010.

This study aimed to validate the relative consistency (relative standard deviation) of swimming force in a fully tethered 6-second maximum crawl sprint test. German junior national team members (M = 33; F = 27) performed three maximum crawl sprint trials under fully-tethered conditions. The overall swimming force exerted on a steel rope was measured by a load cell. The influence of fatigue was eliminated by regression analysis to partial-out specific variance resulting from the test duration on the dependent force variable. For the residual data of the 6-second stationary force-time curve of each S, the standard deviation was calculated, and then expressed as percentage of the mean force. A small intra- and inter-cyclic variation of the swimming force was interpreted as high technical proficiency in the swimmer.

The mean swimming force and the inter- and intra-cyclic variation of the swimming force during the 6-second all-out test were significantly correlated with the personal best competition time in the 50 m freestyle swimming. In males, all crawl sprint times below 24.0 s were associated with relative standard variation coefficients of the exerted force in the fully-tethered swimming test below 70 percent of the mean swimming force of the Ss. In females, no significant correlation between the relative standard deviation of the swimming force and the crawl sprint performance was evident.

Implication. Crawl sprint competition times and a low variation of the propulsive forces exerted in a fully tethered 6-second all-out sprint test confirm the validity of the test procedure in elite male swimmers. On the other hand, tethered swimming does not predict sprint performances in females. [Female 50 m sprinting and longer swimming performances are almost exclusively related to technique, not strength.]

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