Response preparation and posture control. Neuromuscular changes in the older adult.
Response preparation and posture control. Neuromuscular changes in the older adult.
复制标题
反应准备和姿势控制。
DOI：
10.1111/j.1749-6632.1988.tb32964.x
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发表时间：
1988
影响因子：
5.2
通讯作者：
Manchester,D
中科院分区：
文献类型：
--
作者：
Woollacott,M;Inglin,B;Manchester,D
比较年轻人和老年人平衡控制的神经肌肉反应特征的实验表明，这两个群体之间存在许多差异。在后一种人群中，由外部威胁激活的踝部肌肉组织的姿势性肌肉反应延迟稍长，但很明显。此外，在一些试验中，一些老年受试者显示出近端和远端肌肉反应发作的时间逆转。在一些测试的老年受试者中，还存在协同作用内的肌肉反应幅度的相关性的分解。老年人也表现出协同收缩的激动剂和拮抗剂肌肉内的反应协同作用，在更大程度上比年轻人。拮抗剂共同收缩导致的关节僵硬可能是对缺乏与年轻成年人相同程度的姿势反应微调能力的补偿。感觉统合能力的分析表明，在减少或冲突的感觉信息的条件下，平衡控制的损害。当他们被给予不适当的视觉和躯体感觉输入时，一半的老年人在第一次试验中失去了平衡。然而，在大多数情况下，老年人能够在由相同的感官刺激组成的第二次试验中保持平衡。当视觉线索减少限制视野的中央或周边视觉线索，我们发现没有差异的姿势性肌肉反应lativity。然而，老年组比年轻组表现出更多的失去平衡，周边视觉删除或闭上眼睛。此外，在最初的神经系统检查中表现出更强缺陷的受试者与失去平衡的次数之间存在很强的相关性。对老年人手臂随意运动期间姿势和随意肌肉相互作用之间联系的变化的研究表明姿势肌肉前馈激活的潜伏期增加。然而，与年轻人相比，老年人的随意肌肉反应起始时间显示出更大的增加。这表明姿势控制系统激活速度的恶化不是限制自主运动开始速度的唯一因素。测量尚未作出的幅度调节前馈反应的姿势肌肉在自愿的任务。可能的是，两个系统的激活速度的调节不如两个系统之间的适当响应幅度的相关性的微调重要。（400字处截断摘要）
Experiments comparing the characteristics of neuromuscular responses underlying balance control in young and old adults have shown a number of differences between the two populations. Postural muscle response latencies of the ankle musculature activated by external threats to balance are slightly, but significantly, longer in the latter population. In addition, some aging subjects show a temporal reversal of proximal and distal muscle response onset in some trials. There is also a breakdown of the correlation of the amplitude of the muscle responses within a synergy in some of the older subjects tested. Older adults also exhibited cocontraction of agonist and antagonist muscles within a response synergy to a greater extent than young adults. This stiffening of the joints by antagonist cocontraction could be a compensation for the lack of the ability to fine-tune the postural responses to the same degree as the young adults. Analysis of sensory integration abilities showed an impairment in balance control under conditions of reduced or conflicting sensory information. When they were given inappropriate visual and somatosensory inputs, half of the older adults lost balance on the first trial. In most instances, however, the older adults were able to maintain balance during a second trial consisting of the same sensory stimuli. When visual cues were reduced by restricting the visual field to either central or peripheral visual cues, we found no difference in postural muscle response latencies. However, the aging adult group showed more losses of balance than the younger group with peripheral vision removed or with eyes closed. In addition, there was a strong correlation between the subjects that showed stronger deficits on an initial neurological exam and the number of times that balance was lost. Studies on changes in the linkage between postural and voluntary muscle interactions during voluntary arm movements in older adults indicate an increase in the latency of feed-forward activation of postural muscles. However, voluntary muscle response onset latencies show greater increases in the old compared to the young. This suggests that deterioration of the speed of activation of the postural control system is not the only factor that limits the speed of voluntary movement onset. Measurements have not yet been made on the amplitude regulation of feed-forward responses of postural muscles during a voluntary task. It may be that the regulation of the speed of activation of the two systems is less important than the fine tuning of the correlation of appropriate response amplitudes between the two systems.(ABSTRACT TRUNCATED AT 400 WORDS)