兒童踢球動作型式之轉移：工作限制與年齡效應

This study was designed to examine kicking patterns' transition of children as a function of environmental constraints and age-differences. Based on the affordance concept and dynamical systems perspective, it was hypothesized that kicking patterns could be influenced by task constraints and transitions would take place at a specific critical ball size. Participants consisted of 3 groups (5-yr-old, 8-yr-old, and 11-yr-old) each group had of 16 children. Each participant was asked to kick a stationary ball, which was scaled up in individual height with using 4 levels of constraints (height×l0%, 15%, 20%, 25%). Systematic observation using component approach was utilized for analyzing filmed kicking trials. Mixed-design two-way ANOVA, 3(age)×4(ball size) and Tukey's HSD Post Hoc test were administered for statistical analyses. Findings were(1)ages and ball sizes to leg component pattern had the main effect (p＜.05, ES=.68, .11, Power=1, .94), the component pattern of 11-yr-old was significantly higher than that of 5-yr-old, 8-yr-old; in those component patterns of no.1 and no. 2 were significantly lower than those of no.3 and no.4; there was no interaction between ages and task constraints (p＞.05, ES=.02, Power=.25), and (2) transitions appeared at the critical ball size to the different age groups: 5-yr-old group at no. 3 level; both 8-yr-old and 11-yr-old groups at no. 2 level had unstable kicking patterns. The findings showed that the ball size was a factor in changing kicking pattern, kicking pattern was influenced by ball size, which in a specific critical ball size would initiate unstable patterns, and there were age-differences in the kicking patterns.