Publication:

視覺引導對兒童投擲動作的發展效應

中文摘要

本研究以視覺引導（visual guidance）做為環境賦使（affordance）的變項，進而探討不同年齡兒童在有無環境賦使的投擲動作情境中進行運動學特徵比較。研究將以5、7、9、11歲各8名慣用手右手男童為實驗參加者。實驗參加者雙腿伸直坐在長條板凳上，做遮眼及引導各一次的全力投擲。利用Redlake Motion Scope 1000高速攝影機（250Hz）拍攝實驗參加者遮眼及引導的二次投擲動作，並通過SIMI三度空間影片分析系統計算投擲動作的運動學參數變化特徵。統計方法是以混合設計二因子變異數分析進行年齡差異與投擲方式的比較（a = .05），並以Duncan法進行事後比較。研究結果發現年齡越大的兒童投擲球距越遠（F(3, 28) = 22.54，p < .05，h2 = .71，power = 1.00）。而投擲方式的分析顯示引導投擲球距（7.85 ± 2.76 m）顯著的高於遮眼投擲球距（7.28 ± 2.81 m）。而引導投擲動作的垂直球速（3.44 ± 1.57 m/sec）顯著高於遮眼投擲動作（3.05 ± 1.53 m/sec），引導投擲時的出手角度（17 ± 13度）也顯著高於遮眼投擲時（11 ± 16度）。在腕關節出手角速度的分析中發現引導投擲時11歲組（1038 ± 497 deg/sec）明顯的大於5歲組（147 ± 637 deg/sec）。肘關節最大角速度（F(3, 56) = 3.59，p < .05）及肘關節出手角速度（F(3, 56) = 7.54，p < .05）產生了年齡上的顯著差異，引導投擲時晚期兒童比中期兒童產生比較大的角速度變化。11歲組在引導投擲的腕關節出手角速度（1038 ± 497 deg/sec）顯著大於遮眼投擲動作（542 ± 752 deg/sec），而且引導投擲的肘關節出手角速度（1186 ± 273 deg/sec）表現上也顯著大於遮眼投擲動作（864 ± 257 deg/sec）。本研究發現環境賦使效應影響了垂直方向的球速，進而影響了出手角度而增加了投擲球距。環境賦使效應在兒童的投擲動作中，會引起肘關節出手前的動作控制改變，而出手時腕關節及肘關節動作型態均產生年齡差異。在視覺引導下，11歲兒童的肘、腕關節角速度會增大，而5、7、9歲兒童則呈現比較不穩定的狀態。因此以動態系統觀點探討投擲動作的發展效應，個體因為工作項目的不同而產生積極的環境賦使效應。

ABSTRACT

The purpose of this study manipulated the variable of visual guidance, the effect of affordance, to investigate the age difference of kinematical characteristics for overarm throwing in children. Eight volunteer and right-handed boys for each age group (5-, 7-, 9-, and 11-year-old) served as participants in this study. Participants were asked to sit on the bench with legs straightly and to perform overarm throwing forcefully following the sequence of without and with visual guidance. Two high speed cameras (Redlake Motion Scope 1000, 250Hz) and the three-dimensional analysis system (SIMI version 7.0) were used to record and to digitize the throwing movements respectively. Mixed-design two-way ANOVA and Duncan’s test were adopted to analyze the statistical differences for developmental and the effect of visual guidance throwing with an alpha level of .05. The results showed the larger children threw that ball far (F(3, 28) = 22.54, p < .05, h2 = .71, power = 1.00). The main effect showed throwing with visual guidance (7.85 ± 2.76 m) was significant far than throwing without visual guidance (7.28 ± 2.81 m) (p < .05). The vertical velocity of release for throwing with visual guidance (3.44 ± 1.57 m/sec) was faster significantly than throwing without visual guidance (3.05 ± 1.53 m/sec), and the angle of release for throwing with visual guidance (17 ± 13 deg) was also higher significantly than throwing without visual guidance (11 ± 16 deg). The angular velocity of release on wrist for 11-year-old children (1038 ± 497 deg/sec) was higher significantly than 5-year-old (147 ± 637 deg/sec) under the condition of visual guidance. The maximal angular velocity (F(3, 56) = 3.59, p < .05) and angular velocity of release (F(3, 56) = 7.54, p < .05) on elbow were both showed age difference significantly. The angular velocity on elbow for late children was lager than middle children under the condition of visual guidance. For the group of 11-year-old, not only the angular velocity of release on wrist under the condition of visual guidance (1038 ± 497 deg/sec) was higher than the condition of without visual guidance (542 ± 752 deg/sec). But also the angular velocity of release on elbow under the condition of visual guidance (1186 ± 273 deg/sec) was higher than the condition of without visual guidance (864 ± 257 deg/sec). This study indicated that the effect of affordance, visual guidance, enhanced the performance of the throwing distance in the cause of vertical velocity of release to increase the angle of release. Under the condition of visual guidance, the pattern of throwing control on elbow was influenced before release. And there were age difference significantly on wrist and elbow at the moment of release. The angular velocity on wrist and elbow were increasing for 11-year-old children, but these were inconsistent for 5- to 9-year-old. From the aspect of the dynamical systems, the behavior of the development of throwing was constrained through the difference of task to process the effect of affordance positively.