Smiley-Oyen A L, Lowry K A, Kerr J P
Motor Control and Learning Research Laboratory, Department of Health and Human Performance, Iowa State University, Ames 50011, USA.
J Mot Behav. 2007 Mar;39(2):103-14. doi: 10.3200/JMBR.39.2.103-114.
Eight people with Parkinson's disease (PD), 8 age-matched older adults, and 8 young adults executed 3-dimensional rapid aiming movements to 1, 3, 5, and 7 targets. Reaction time, flight time, and time after peak velocity to the 1st target indicated that both neurologically healthy groups implemented a plan on the basis of anticipation of upcoming targets, whereas the PD group did not. One suggested reason for the PD group's deficiency in anticipatory control is the greater variability in their initial force impulse. Although the PD group scaled peak velocity and time to peak velocity similarly to the other groups, their coefficients of variation were greater, making consistent prediction of the movement outcome difficult and thus making it less advantageous to plan too far in advance. A 2nd finding was that the PD group exhibited increased slowing in time after peak velocity in the final segments of the longest sequence, whereas the other 2 groups did not. The increased slowing could be the result of a different movement strategy, increased difficulty modulating the agonist and antagonist muscle groups later in the sequence, or both. The authors conclude that people with PD use more segmented planning and control strategies than do neurologically healthy older and young adults when executing movement sequences and that the locus of increased bradykinesia in longer sequences is in the deceleration phase of movement.
八名帕金森病（PD）患者、八名年龄匹配的老年人和八名年轻人对1、3、5和7个目标进行了三维快速瞄准动作。反应时间、飞行时间以及达到第一个目标的峰值速度后的时间表明，两个神经功能正常的组都是基于对即将到来的目标的预期来实施计划的，而帕金森病组则不然。帕金森病组在预期控制方面存在缺陷的一个可能原因是其初始力冲动的变异性更大。尽管帕金森病组在峰值速度和达到峰值速度的时间方面与其他组的缩放方式相似，但其变异系数更大，这使得对运动结果进行一致的预测变得困难，因此提前过多计划就不那么有利了。第二个发现是，帕金森病组在最长序列的最后阶段，峰值速度后的时间出现了增加的减速，而其他两组则没有。增加的减速可能是不同运动策略的结果，也可能是在序列后期调节主动肌和拮抗肌群的难度增加，或者两者兼而有之。作者得出结论，帕金森病患者在执行运动序列时，比神经功能正常的老年人和年轻人使用更多的分段计划和控制策略；并且在较长序列中运动迟缓增加的部位是在运动的减速阶段。
