This study examined variability in throwing speed and spatial error to test the prediction of an inverted-U function (i.e., impulse-variability [IV] theory) and the speed-accuracy trade-off. Forty-five 9- to 11-year-old children were instructed to throw at a specified percentage of maximum speed (45%, 65%, 85%, and 100%) and hit the wall target. Results indicated no statistically significant differences in variable error across the target conditions (p = .72), failing to support the inverted-U hypothesis. Spatial accuracy results indicated no statistically significant differences with mean radial error (p = .18), centroid radial error (p = .13), and bivariate variable error (p = .08) also failing to support the speed-accuracy trade-off in overarm throwing. As neither throwing performance variability nor accuracy changed across percentages of maximum speed in this sample of children as well as in a previous adult sample, current policy and practices of practitioners may need to be reevaluated.
Sergio L. Molina and David F. Stodden
Andrew Chappell, Sergio L. Molina, Jonathon McKibben and David F. Stodden
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.
Danielle Nesbitt, Sergio L. Molina, Maria Teresa Cattuzzo, Leah E. Robinson, David Phillips and David Stodden
This paper examined relationships between qualitative (developmental sequences) and quantitative (time) performance in rising from a supine position in early childhood. One hundred twenty two children ranging in age from 3 to 5 years were videotaped for five trials of rising from a supine position. Children’s performance on the supine-to-stand (STS) task was quite variable in terms of both qualitative movement patterns and time (mean = 2.37 s, SD = .60). Results: Component sequences were moderately to strongly correlated with each other (r = .387 to .791). Upper-extremity (r = –.383) and axial (r = –.416) component levels also were inversely correlated with STS time. Results indicated a strong coordinative link between the development of trunk control (i.e., axial movement) and upper-extremity movement levels (r = .791), and together they demonstrated the strongest impact on the ability to rise quickly. These data provide important information relating to a child’s motor development that may have clinical relevance for diagnosis. It provides also a greater understanding on how to improve performance on this task. Future research should examine qualitative and quantitative aspects of STS performance to understand its predictive utility as a lifespan assessment of motor competence and its potential importance as a measure to predict healthrelated variables and functional capability across the lifespan.
A. Paige Lane, Sergio L. Molina, DaShae A. Tolleson, Stephen J. Langendorfer, Jacqueline D. Goodway and David F. Stodden
Examining the underlying processes that contribute to fundamental movement pattern development and their relationship to performance outcomes is essential to effectively promote competence and mastery. However, few studies have examined the associations between process-oriented movement assessments and performance. The purpose of this study was to hypothesize component developmental sequences for the landing phase of the standing long jump and test them via a pre-longitudinal screen with cross-sectional data from children and young adults. Component levels of the standing long jump landing were identified for shank, foot, and arm action on 347 children ages 4–12 years and 48 adults ages 18–25 years. Modal profile curves were plotted for each component across age groups. In addition, modal sequences, height, and mass were regressed against jump distance as a secondary method of developmental validation. Component level trajectories indicated sufficient evidence for developmental trends of each component. Explained variance in jump distance by sequences, height, and mass varied across age groups and sex. Our findings indicate the proposed component sequences for landing may demonstrate adequate developmental validity; however, longitudinal validation is needed. Landing patterns play an important role in standing long jump performance and warrant more attention in motor development research.