Mohammadali Esmaeilzadeh; Mehdi Shahbazi; Ali Akbar Jaberimoghaddam; Shahzad Tahmasebi; Elham Shirzad
Abstract
Behavioral studies in team sports are typically constrained by dynamic factors, such as positioning of defenders for interception. Handball player have to coordinate their steps when running to throw a ball on goal from a different positions. In this study were analyzed the movement patterns during locomotors ...
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Behavioral studies in team sports are typically constrained by dynamic factors, such as positioning of defenders for interception. Handball player have to coordinate their steps when running to throw a ball on goal from a different positions. In this study were analyzed the movement patterns during locomotors pointing, throwing velocity and accuracy of 12 succesful elite handball players under defensive constraints (defender- absent, defender-far, defender-near, or defender pairing). It was captured data from the locomotors patterns of the attacking participant by speed camera with 120Hz, throwing speed by sports radar gun and throwing accuracy by camera. ANOVA with repeated measures and Bonferroni post hoc test and Friedman test was used to analyze effects of these constraints on gait and throwing parameters. In addition to Pearson and Spearman correlation coefficient test was used to analyze speed-accuracy trade off (P<0.05). The results revealed significant differences in overall mean movement velocity, first and second step mean velocity, first and second step mean length. For the mean foot/gate area distance variability was shown pattern of ascending/descending variability in all defense conditions. Since regulation of offensive players was continuous and based on perception of current and required behaviors, results supported from perception-action coupling and prospective control models of locomotors pointing. Also it is suggested that the technical aspects of the running and throwing in handball can affect by nested tasks constraints.
Bahram Ghafari; Mehdi Shahbazi; Mehdi Aghapour; Elham Shirzad
Abstract
Meta-stability is a relatively stable region in which system components tend to cooperate to reach performance goals of movement while maintaining their separate and flexible characters. Participants were assigned to 3 skill groups: coordination (n=10), coordination control (n=10), and optimized ...
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Meta-stability is a relatively stable region in which system components tend to cooperate to reach performance goals of movement while maintaining their separate and flexible characters. Participants were assigned to 3 skill groups: coordination (n=10), coordination control (n=10), and optimized control (n=10). Each two fencers fought in each group. Results of cluster analysis and empirical density indicated the emergence of a metastable region in coordination control group (between 1.689276- 2.270372), two metastable regions in optimized control group (between 0.9824658- 1.00113699 and 1.843131-2.333738) and no metastable region in coordination group. Moreover, the binomial test showed that the proportion of using modes of actions in metastable regions in coordination control and optimized control groups had no significant difference (P=0.4888). But the extent of metastable region in the coordination control group was significantly greater. Findings of this study showed that fencers' motor system is metastable depending on their skill level and the extent of metastable regions was different in each level. To design learning and organizing practice, sport coaches can lead the athletes to metastable regions to emerge the most functional motor responses.
