Elderly show decreased adjustments of motor synergies in preparation to action
Elderly show decreased adjustments of motor synergies in preparation to action
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DOI：
10.1016/j.clinbiomech.2006.08.005
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发表时间：
2007-01-01
影响因子：
1.8
通讯作者：
Latash, Mark L.
中科院分区：
文献类型：
--
作者：
Olafsdottir, Halla;Yoshida, Naoki;Latash, Mark L.
背景衰老与手的灵活性下降有关。最近的研究结果已经确定了老年人多指协同作用的变化。目前的工作的目的是研究与年龄相关的变化，调整多指协同作用，准备一个快速有针对性的力脉冲生产task.Methods。右撇子的老年人和年轻人通过用右手的四个手指按压单独的力传感器来产生快速的力脉冲。在力脉冲之前，受试者产生恒定的低水平的总力。计算每个受试者和每个条件下每个时间样本的多指协同作用指数。在稳定状态的生产力，科目显示出共同变化的命令，稳定的总力量的手指。该共变的指数在力脉冲开始之前开始降低（预期协同调节）。预期协同作用的调整，在年轻的科目开始较早，并大于老年人。特别地，年轻和老年受试者分别在力脉冲开始前约150 ms和约50 ms开始显示出显著的预期协同调节。两组之间在其他性能指标如反应时间、达到峰值力的时间和峰值力的大小方面没有显著差异。我们的结论是，健康的老龄化与减少前馈调整的多指协同作用，准备采取行动。这可能导致与年龄相关的手部功能下降。基于与年龄相关的变化在预期的姿势调整和预期的协同调整的相似性，我们提出了一个假设，这两种现象可能有共同的机制。(c)2006爱思唯尔有限公司保留所有权利。
Background. Aging is associated with decreased manual dexterity. Recent findings have identified changes in multi-finger synergies in elderly individuals. The purpose of current work was to study age-related changes in adjustments of multi-finger synergies in preparation to a quick targeted force pulse production task.Methods. Right-handed elderly and young subjects produced quick force pulses by pressing on individual force sensors with the four fingers of the right hand. Prior to the force pulse, the subjects produced a constant low level of the total force. An index of multi-finger synergies was computed across trials for each time sample for each subject and each condition.Findings. During steady-state force production, subjects showed co-variation of commands to fingers that stabilized the total force. An index of this co-variation started to decrease prior to the initiation of the force pulse (anticipatory synergy adjustment). Anticipatory synergy adjustments in young subjects started earlier and were larger than in elderly subjects. In particular, young and elderly subjects showed significant anticipatory synergy adjustments starting about 150 ms and about 50 ms prior to the force pulse initiation, respectively. There were no significant differences between the two groups in other indices of performance such as reaction time, time to peak force, and magnitude of the peak force.Interpretation. We conclude that healthy aging is associated with decreased feed-forward adjustments of multi-finger synergies in preparation to action. This may contribute to the age-related decline in the hand function. Based on similarities in age-related changes in anticipatory postural adjustments and anticipatory synergy adjustments we suggest a hypothesis that the two phenomena may share common mechanisms. (c) 2006 Elsevier Ltd. All rights reserved.