本研究的目的主要在探討不同的工作限制對單手過肩投擲動作的影響。實驗參加 者為 13 位國小中年級的男學童，平均年齡為 9.5 歲， 以手拿網球投擲動作做為本實驗的 工作，工作的限制有兩種：(一 ) 用力性投擲，及 (二 ) 準確性投擲。 本研究的自變項為 工作限制的類型；依變項為不同的投擲動作的因素的層次。 實驗開始之前，先對 2 9 位實 驗參加者施測兩種不同工作限制的投擲前測，經檢測其投擲速度，及計算投擲點距目標區中 心點的距離後，篩選合於規定的實驗參加者，之後對其投擲動作進行動作因素的層次評定。 經弗里曼二因子等級變異數分析、相依樣本二因子變異數分析，及百分比描述統計分析，發 現不同的工作限制與投擲動作因素之間有交互作用存在；此即，不同的工作限制對軀幹動作 層次的影響，須視所用何種投擲方式而定。動作因素在不同的工作限制下也有顯著的差異； 此外，從描述統計中顯示軀幹動作的轉移現象，比其它動作因素受工作限制的改變較大。

　　　　　The purpose of this study was to examine the overhand throwing patterns as a function of task constraints. Thirteen male elementary school students (mean age= 9.5 years) served as participants, and were asked to perform an overhand throwing under two task constraints:(1) throwing for force, and (2) throwing for accuracy. The independent variables were task constraints, and the dependent variables were the components of throwing patterns. According to the pretests of throwing speed and accuracy, 13 out of 29 participants were screened out to serve as participants and went through motor component analyses. The scores of trials were analyzed using Nonparametric Friedman Two-way ANOVA, Repeated Two-way ANOVA, and percentage descriptive statistics. It was found that there were interactions between the task constraints and the throwing components, the task constrained the trunk movement, and the motor components had been significantly affected by the task constraints. Furthermore, the descriptive statistics showed that trunk movement had more transitions phenomenon under task constraints.