AN EXAMINATION OF KINEMATIC VARIABILITY OF MOTION ANALYSIS IN SPRINT HURDLES

Eight trials each of 7 athletes (4 women and 3 men) were videotaped an d digitized in order to investigate the variation sources and kinemati c variability of video motion analysis in sprint hurdles. Mean coeffic ients of variation (CVs) of individuals ranged from 1.0 to 92.2% for w omen and from 1.2 to 209.7% for men. There were 15 and 14 variables, r espectively, in which mean CVs revealed less than 5% variation. In red igitizing, CVs revealed less than or equal to 1.0% for 12 variables fo r the women's trials and 10 variables for the men's trials. These resu lts, together with variance components (between-subjects, within-subje ct, and redigitizing), showed that one operator and the analysis syste m together produced repeatable values fbr most of the variables. The m ost repeatable variables by this combination were displacement variabl es. However, further data processing (e.g., differentiation) appeared to have some unwanted effects on repeatability. Regarding the athletes ' skill, CVs showed that athletes can reproduce most parts of their pe rformance within certain (reasonably low) limits.