Kinematic analysis of the backstroke start : differences between backstroke specialists and non-specialists
Deutscher übersetzter Titel: | Kinematische Analyse des Rückenschwimmstarts : Unterschiede zwischen Rückenschwimmspezialisten und -Amateuren |
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Autor: | Takeda, Tsuyoshi; Itoi, Osamu; Takagi, Hideki; Tsubakimoto, Shozo |
Erschienen in: | Journal of sports sciences |
Veröffentlicht: | 32 (2014), 7, S. 635-641, Lit. |
Format: | Literatur (SPOLIT) |
Publikationstyp: | Zeitschriftenartikel |
Medienart: | Elektronische Ressource (online) Gedruckte Ressource |
Sprache: | Englisch |
ISSN: | 0264-0414, 1466-447X |
DOI: | 10.1080/02640414.2013.845678 |
Schlagworte: | |
Online Zugang: | |
Erfassungsnummer: | PU201408007581 |
Quelle: | BISp |
Abstract
The purpose of this study was to clarify factors to perform the hole-entry technique in the backstroke start. A total of 16 well-trained Japanese competitive swimmers were divided into two groups (backstroke specialists and non-specialists) to compare their backstroke start motions. Their backstroke motions were videotaped, and two-dimensional co-ordinates for the swimmers were obtained from the video images using direct linear transformation methods. A non-paired t-test and Mann–Whitney U-test were used to analyse the statistical difference of the kinematic variables between the groups. Backstroke specialists showed a significantly shorter 5 m time (P = 0.009, effect size = –1.54), a significantly higher position of the toe (P = 0.010, effect size = 1.47) at signal and of the hip at toe-off (P = 0.002, effect size = 1.94), a significantly larger hip joint angle at toe-off (P = 0.007, effect size = 1.60) and a significantly higher angular velocities of the hip joints (45–85%; P < 0.05) for the normalised time as compared to that of non-specialists. An earlier initiation of the extension and the maintenance of a higher extension speed at the hip joints were important factors in achieving an arched-back posture, which facilitated and water entrance with a small entry range. Verf.-Referat