過去的研究發現單手過肩投擲動作的層次高低及穩定性明顯地受球的尺寸 大小影響。本研究以動態系統為理論依據，以實際教育或比賽用球進行檢驗， 目的在探討相同年齡的學童，在躲避球過肩投擲動作層次及穩定性的實驗中， 如何受個體差異--手掌寬度的影響。實驗參加者是從國小六年級375名男學 生中，篩選手掌較長者和手掌較短者各13名，施做躲避球用力對牆投擲測 驗。實驗的自變項為學童的手掌寬度，依變項為投擲的動作層次及穩定性。經 評分者分析其動作層次、弗里曼等級二因子變異數分析、及二因子混合設計變 異數分析後，發現：(一)同年齡成長情況不同，對單手投擲的軀幹動作表現有顯 著差異，(二)同年齡成長情況不同，對單手投擲的穩定性沒有差異。

　　　　　Previous research showed that the throwing patterns and its stability of children were affected by the ball sizes. This study investigated overhand throwing patterns using the educational and competition ball. The purpose of this study, based on the dynamical systems concept, was to examine how the overhand throwing componetnts and patterns of children with the same age were affected by hand width. From 375 male elementary school children, 26 were screened out and served as participants. All the participants were divided into long and short hand-width groups. Participants were asked to perform over-hand throw with dodge ball, and the throwing patterns were recorded by video-taping technique. The independent variable was hand width. and the dependent variable was throwing pattern and its stability. Video tapes were analyzed for the movement patterns, and the results were analyzed using Friedman two-way ANOVA and two-ways mixed ANOVA. Two conclusion were derived： (a) in the same age group, differences in trunk actions was found in the same age groups, (b) in the same age group, no difference of throwing pattern was found in the stability.