Diagnosis of Swimming Technique by fully tethered Swimming

Titelangaben

Hohmann, Andreas ; Fehr, Ulrich ; Fankel, Julia:
Diagnosis of Swimming Technique by fully tethered Swimming.
2010
Veranstaltung: XIth International Symposium on Biomechanics and Medicine in Swimming , 16.-19.06.2010 , Oslo.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung , Poster )

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Abstract

Introduction:
Dopsaj, Matkovic, and Zdravkovic (2000) showed that fully tethered swimming (FTS) is a worthwhile tool for measuring maximum swimming force (Fmax), and also valid to predict 50-m-crawl sprint times. In addition to that, in this study it is assumed that a fully tethered crawl swim test can also be used to diagnose swimming technique by quantifying the intra- and intercyclic variation of the propulsive force. According to Miyashita (1999), a small intra- and intercyclic variation of the swimming force is interpreted as a high technical proficiency of the swimmer. Thus, the study aims at the validation of the Relative Standard Deviation (RelSD) of the swimming force in a fully tethered 6-s-maximum crawl sprint test.

Methods:
33 male and 27 female elite swimmers of the German junior national team performed 3 maximum crawl sprint trials under fully tethered conditions. The over all swimming force exerted on a steel rope was measured by a strain gauge. In a first step, the influence of increasing fatigue was eliminated by partializing out the specific variance resulting from the test duration (time) on the dependent variable swimming force by means of a regression analysis. In a second step, for the residual data of the 6 s stationary force-time curve of each swimmer (Figure 1), the individual standard deviation was calculated, and then expressed as percentage of the mean force.

Results:
Not only the mean swimming force, but also the inter- and intracyclic variation of the swimming force during the 6-seconds all-out test is significantly correlated with the personal best competition time in the 50-m-freestyle swimming. In the male group (see Figure 2), all crawl sprint times below 25.0 s are associated with relative standard variation values of the exerted force in the fully tethered swimming test that are smaller than 75 percent of the mean swimming force of the individuals. In the girls group, no significant correlation (rtc=.08; p=.337; n=29) between the RelSD of the swimming force and the crawl sprint performance could be found.

Discussion:
The significant correlation between the crawl sprint competition times and a low variation of the propulsive forces exerted in a fully tethered 6-seconds all-out sprint test underline the validity of the test procedure in international calibre junior swimmers, at least in males.