title: Examining Impulse-Variability in Kicking.
abstract: This study examined variability in kicking speed and spatial accuracy to test the impulse-variability theory prediction of an inverted-U function and the speed-accuracy trade-off. Twenty-eight 18- to 25-year-old adults kicked a playground ball at various percentages (50-100%) of their maximum speed at a wall target. Speed variability and spatial error were analyzed using repeated-measures ANOVA with built-in polynomial contrasts. Results indicated a significant inverse linear trajectory for speed variability (p < .001, η2= .345) where 50% and 60% maximum speed had significantly higher variability than the 100% condition. A significant quadratic fit was found for spatial error scores of mean radial error (p < .0001, η2 = .474) and subject-centroid radial error (p < .0001, η2 = .453). Findings suggest variability and accuracy of multijoint, ballistic skill performance may not follow the general principles of impulse-variability theory or the speed-accuracy trade-off.
authors.affiliation: Los Angeles Angels Baseball Club, Jonestown, TX.
authors.forename: Andrew
authors.initials: A
authors.lastname: Chappell
authors.forename: Sergio L
authors.initials: SL
authors.lastname: Molina
authors.forename: Jonathon
authors.initials: J
authors.lastname: McKibben
authors.forename: David F
authors.initials: DF
authors.lastname: Stodden
mesh_terms: D000328:Adult; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D055815:Young Adult