van der Meulen J H, Denier van der Gon J J, Gielen C C, Gooskens R H, Willemse J
Department of Child Neurology, University Hospital Utrecht, The Netherlands.
Dev Med Child Neurol. 1991 Jan;33(1):40-54. doi: 10.1111/j.1469-8749.1991.tb14784.x.
The mechanisms underlying accuracy in fast goal-directed arm-movements were investigated in normal and clumsy children in two age-groups, six to seven and 10 to 11 years. Clumsy children in both age-groups had a longer movement time than normal children; this difference increased slightly when there was visual feedback. For both normal and clumsy children, the relative variability of the total distance moved was smaller than that of the distance moved during acceleration, indicating a variability reduction mechanism in the course of a movement. In the six- to seven-year-old group, the relative variability of the distance moved during acceleration and of the total distance was larger for clumsy than for normal children; this did not reach significance in the 10- to 11-year-old group. It is suggested that motor difficulties are linked to inaccuracy in open-loop control processes and to less efficient use of visual feedback.
在两个年龄组（6至7岁和10至11岁）的正常儿童和动作笨拙儿童中，研究了快速目标导向手臂运动准确性的潜在机制。两个年龄组的动作笨拙儿童的运动时间都比正常儿童长；当有视觉反馈时，这种差异会略有增加。对于正常儿童和动作笨拙儿童来说，移动总距离的相对变异性小于加速过程中移动距离的相对变异性，这表明在运动过程中存在变异性降低机制。在6至7岁组中，动作笨拙儿童在加速过程中移动距离和总距离的相对变异性比正常儿童大；这在10至11岁组中没有达到显著水平。有人提出，运动困难与开环控制过程中的不准确以及视觉反馈的低效利用有关。
