Int J Sports Med 2009; 30(11): 779-781
DOI: 10.1055/s-0029-1234059
Rapid Communication

© Georg Thieme Verlag KG Stuttgart · New York

Does the Hip Reflect the Centre of Mass Swimming Kinematics?

P. Figueiredo 1 , J. P. Vilas Boas 1 , J. Maia 1 , P. Gonçalves 1 , R. J. Fernandes 1
  • 1University of Porto, Faculty of Sport, Centre of Research, Education, Innovation and Intervention in Sport, Porto, Portugal
Weitere Informationen

Publikationsverlauf

accepted after revision June 29, 2009

Publikationsdatum:
16. Oktober 2009 (online)

Preview

Abstract

The purpose of this study was to determine the relationship between the hip point and the centre of mass for kinematical parameters (displacement, velocity and acceleration) in the three axes of motion. One complete stroke cycle was analyzed in eight swimmers performing a 25 m front crawl swim test at high intensity. Within-subject correlation coefficients were computed between the centre of mass and both hips, as well as mean of the errors, RMS error and a paired sample t-test. High correlation coefficients were found for the displacement in the horizontal direction (r=1.00 for both hips) and low to moderate correlation coefficients (r=−0.01 to r=0.54) were found for all other studied variables. Moreover, moderate to large RMS errors were observed: (i) between 0.05 and 0.15 for the displacement; (ii) between 0.16 and 0.30 for the velocity and (iii) between 5.28 and 7.86 for the acceleration. Complementarily, RMS errors for the intracyclic velocity variation were between 0.07 and 0.18. Considering the centre of mass and hip values statistical differences were found in velocity in x, acceleration in x and y, and intracyclic velocity variation in y axes. Therefore, results suggest that the hip point does not represent most kinematical parameters of the estimated centre of mass in front crawl swimming.

References

Correspondence

Prof. R. J. Fernandes

University of Porto

Faculty of Sport

Swimming

Rua Dr. Plácido Costa

91

4200

Portugal

Telefon: +351225074763

Fax: +351225500687

eMail: ricfer@fade.up.pt