In this study we investigated redundancy control in joint action. Ten participantpairs (dyads) performed a virtual lifting task in which isometric forces needed to be generated with two or four hands. The participants were not allowed to communicate but received continuous visual feedback of their performance. When the task had to be performed with four hands, participants were confronted with a redundant situation and between-hand force synergies could, in principle, be formed. Performance timing, success rates, cross-correlations, and relative phase analyses of the force-time functions were scrutinized to analyze such task-dependent synergies. The results show that even though the dyads performed the task slower and less synchronized in the joint than in the solo conditions, the success rates in these conditions were identical. Moreover, correlation and relative phase analyses demonstrated that, as expected, the dyads formed between-participant synergies that were indicative of force sharing in redundant task conditions.
Jurjen Bosga and Ruud G. J. Meulenbroek
John Stoszkowski and Dave Collins
A reflective approach to practice is consistently espoused as a key tool for understanding and enhancing coach learning and raising the vocational standards of coaches. As such, there is a clear need for practical tools and processes that might facilitate the development and measurement of “appropriate” reflective skills. The aim of this preliminary study was to explore the use of online blogs as a tool to support refection and community of practice in a cohort of undergraduate sports coaching students. Twenty-six students (6 females, 20 males) reflected on their coaching practice via blogs created specifically for refection. Blogs were subjected to category and content analysis to identify the focus of entries and to determine both the emergent reflective quality of posts and the extent to which an online community of practice emerged. Findings revealed that descriptive refection exceeded that of a critical nature, however, bloggers exhibited a positive trajectory toward higher order thinking and blogs were an effective platform for supporting tutor-student interaction. Despite the peer discourse features of blogs, collaborative refection was conspicuous by its absence and an online community of practice did not emerge.
Edited by Thomas Rowland
Over the past 30 years almost all world-class United States sprinters have been black. There were also many fast black sprinters in the United States before the 1960s, but in addition there were a considerable number of world-class white sprinters. In fact, during the 1940s and 1950s the fastest men were white. This was not the case during the 1930s, when the best male sprinters were black. This essay discusses the phenomenon and attempts to give reasons for it. Sociological explanations seem considerably more plausible than physical characteristics based on perceived racial differences.
David Kahan and Virginie Nicaise
Curriculum interventions aimed at increasing physical activity in schools may prove useful in contexts where changes in policy/environment are not feasible. Design/evaluation of interventions targeting minority groups is important in light of well-publicized health disparities. Religious minorities represent a special subset that may positively respond to interventions tailored to their unique beliefs, which to date have been relatively underreported.
Muslim American youth (n = 45) attending a parochial middle school participated in a religiously- and culturally-tailored 8-wk, interdisciplinary pedometer intervention. School-time ambulatory activity was quantified using a delayed multiple-baseline across subjects ABA design. Visual analysis of graphic data as well as repeated-measures ANOVA and ANCOVA and post hoc contrasts were used to analyze step counts including the moderating effects of day type (PE, no-PE), gender, BMI classification, grade, and time.
The intervention elicited modest increases in males’ steps only with effect decay beginning midintervention. BMI classification and grade were not associated with changes in steps.
Full curricular integration by affected classroom teachers, staff modeling of PA behavior, and alternative curriculum for girls’ PE classes may further potentiate the intervention.
Louise Foley and Ralph Maddison
There has been increased research interest in the use of active video games (in which players physically interact with images onscreen) as a means to promote physical activity in children. The aim of this review was to assess active video games as a means of increasing energy expenditure and physical activity behavior in children. Studies were obtained from computerised searches of multiple electronic bibliographic databases. The last search was conducted in December 2008. Eleven studies focused on the quantification of the energy cost associated with playing active video games, and eight studies focused on the utility of active video games as an intervention to increase physical activity in children. Compared with traditional nonactive video games, active video games elicited greater energy expenditure, which was similar in intensity to mild to moderate intensity physical activity. The intervention studies indicate that active video games may have the potential to increase free-living physical activity and improve body composition in children; however, methodological limitations prevent definitive conclusions. Future research should focus on larger, methodologically sound intervention trials to provide definitive answers as to whether this technology is effective in promoting long-term physical activity in children.
Edited by Thomas Rowland
Manuel E. Hernandez, Erin O’Donnell, Gioella Chaparro, Roee Holtzer, Meltem Izzetoglu, Brian M. Sandroff and Robert W. Motl
in this aging population. Standard tests of gait function in persons with MS include the timed 25-foot walk, yet increased sensitivity may be achieved through the use of more balance-demanding walking tasks ( Stellmann et al., 2014 ). In this study, we examine virtual beam walking (VBW) tasks on a
Dustin R. Grooms, Adam W. Kiefer, Michael A. Riley, Jonathan D. Ellis, Staci Thomas, Katie Kitchen, Christopher A. DiCesare, Scott Bonnette, Brooke Gadd, Kim D. Barber Foss, Weihong Yuan, Paula Silva, Ryan Galloway, Jed A. Diekfuss, James Leach, Kate Berz and Gregory D. Myer
the perceptual-motor and neurocognitive challenges of interacting with a dynamic athletic environment. The advent of virtual reality (VR) technologies provides a means to overcome this limitation to assess motor pattern transfer to sport. VR allows athletes to be immersed in environments that mimic
Marco J. Konings, Jordan Parkinson, Inge Zijdewind and Florentina J. Hettinga
to athletes in competitive sports. 5 Indeed, the presence of a virtual opponent has been shown to improve cycling performance, 6 – 8 and the pacing behavior of the virtual opponent has been shown to affect the initial pace of cyclists in laboratory-controlled conditions. 7 The performance