RELIABILITY ASSESMENT OF KINEMATIC VARIABLES IN THE MOTION ANALYSIS OF FEMALE SPRINT HURDLES

Abstract

INTRODUCTION: There has been very little attention paid to the reliability of motion analysis in sport applications. Thus, the aim of this study was to investigate the reliability of kinematic variables in practical applied sports research utilising sprint hurdles. METHODS: Eight sprint hurdle clearances each from four national level female athletes were videotaped and digitised. The 3-D measurement set-up follows the procedure reported by Salo et al. (1997). Following the calculation of 28 kinematic variables, the reliability of the mean of eight trials was determined by using the ANOVA method (Vincent, 1995). The reliability of a certain number of measurements were estimated using the equation presented in Baumgartner (1989). RESULTS: The range of the reliability values across the eight trials [R(8)] and a single trial [R(1)] as well as the number of variables to gain different reliability levels when estimated from a different number of measurements are presented in table 1. {Table 1.} DISCUSSION: There are no absolute categories or significance test for reliability. However, the estimated R(1) showed that a single trial is not particularly representative for the kinematic analysis of sport events such as sprint hurdles. Athletes were not able to repeat all the specifics of the demanding skill in every trial and although motion analysis can be regarded as an objective method, the manual digitising involves a subjective evaluation. Finally, it is possible that homogenous performance at a group level may bias reliability values and closer examination of the results showed that this may have been the case in two variables. REFERENCES: Baumgartner, T.A. (1989). Norm-referenced Measurement: Reliability. In: Safrit, M.J. and Wood, T.M. (eds.). Measurement Concepts in Physical Education and Exercise Science. Champaign, Illinois, pp. 45-67, 1989. Salo, A., Grimshaw, P.N., Viitasalo, J.T. (1997). Reliability of Variables in the Kinematic Analysis of Sprint Hurdles. Med. Sci. Sports Exerc. 29, 383-389, 1997. Vincent, W.J. (1995). Statistics in Kinesiology. Champaign, Illinois, pp. 168- 181, 1995.