Publication:

速跑跨躍障礙的知覺─行動連結控制

本研究主要目的是針對直接知覺的觀點，觀察中晚期兒童在快速跑跨越障礙物的知覺─行動連結，並探討因為練習帶來的動作控制與其適應性之改變。實驗以10名中晚期男童為實驗參加者，平均年齡9.3±0.3歲，身高132.9±5.6公分，體重31.4±9.2公斤，練習5天，每天12次衝刺跑跨越前方15公尺處的膝高障礙物。研究通過高頻雷射距離測量系統（LDM 300CTM，100Hz）進行動作過程的資料收集，並以AcqKnowledge 3.7.2版軟體分析助跑過程，在練習前後與遷移測驗的步長、步頻、速度與落腳位置等運動學參數。並以重複量數二因子變異數分析和t考驗，比較練習前後與其對於動作的適應在每步之行為改變（α=.05）。結果顯示，在迫近階段步長的運動學特徵在練習初期調整最大；個體在練習後期的落腳位置變異性最大，說明個體練習後，經由每一步的修正及自我重組，達到熟練跨躍障礙物的動作技能。而在學習的遷移效應上，個體在起跳前的第5步產生最大速度，當增加難度時，個體會降低落腳位置變異性，並藉由逐步減緩速度直至起跳瞬間；降低難度的動作，與練習後期落腳位置標準差無顯著差異，且隨接近障礙物而減緩跑步速度，但在起跳瞬間卻會產生突然加速動作。另外，個體會採用不同的策略以調整每一步的變異量，顯示有個別差異存在。在跑步速度的加速或減速上，是採取調整步長，以作為完成跨躍助跑動作的表現。

The purpose of this study was based on the concept of direct perception to investigate the change of motor control and adaptability in perception-action coupling under speed hurdle practice for middle/late children. Ten boys (mean age 9.3□0.3 years; mean height 132.9□5.6 cm; mean body mass 31.4□9.2 kg) participated in this study. Participants were asked to practice 15m sprint and to hurdle a knee height obstructer that lasted for 5 days with 12 times per day. A laser distance measurement system (LDM 300CTM, 100Hz) and an AcqKnowledge version 3.7.2 were used respectively to record the process of speed hurdle and to analyze the kinematical parameters (i.e., stride length, stride rate, velocity, and landing distance) of pre-practice, post-practice, and transfer tests. Repeated measures two-way ANOVA and t-test were used to with an alpha level .05 were adopted to analyze the statistical difference for the behavior change of stride parameters. The results showed the regulation of stride length during the initial practice was larger than the post-practice in zeroing-in phase. The variability of landing distance during the post-practice was lager than the initial practice, and it was indicated that the individual acquired the motor skill to perform speed hurdle through the regulation of every stride and the self-organization of human body. The effects of transfer of learning showed the maximal velocity was raised in the fifth step before jump, and the individual not only reduced sprint velocity step by step until the instant of jump but also reduced the variability of landing distance under the task of difficulty increased. Under the task of difficulty decreased, the variability of landing distance had no any statistics difference with post-practice, and the velocity in jumping instant burst raise that followed the sprint velocity decrease step by step for approaching. Moreover, it existed individual difference that the participant to regulate the variability in different strategies for every stride. The increasing or decreasing the approaching velocity to perform the movement of speed hurdle did mainly in the strategy of the regulation of stride length.