Alteration of motor-unit discharge characteristics in aged humans.
Alteration of motor-unit discharge characteristics in aged humans.
复制标题
老年人运动单位放电特性的改变。
DOI：
10.1093/ptj/64.1.29
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发表时间：
1984
期刊：
影响因子：
3.2
通讯作者：
Nancy L. Urbscheit
中科院分区：
文献类型：
--
作者：
Roger M. Nelson;Gary L Soderberg;Nancy L. Urbscheit
本研究的目的是确定和比较年轻和老年受试者在小指展肌最大随意收缩 (MVC) 5%、10% 和 20% 期间单运动单位动作电位 (SMUAP) 的放电特征。将 30 岁的 60 岁至 90 岁的老年受试者与 20 岁至 35 岁的受试者进行比较。使用特殊构造的细线双线记录电极，并通过交互式计算机处理来识别 SMUAP。尽管结果没有达到统计学上显着的水平，但他们显示，70至79岁年龄组在MVC的三个百分比中的每一个中具有最长的平均峰间间隔（ISI）。延长的 ISI 表明运动单位放电速率缓慢。此外，70至79岁组具有统计显着的浮动标准差，表明放电变异性增加，并且负浮动序列相关系数显着不同。描述 70 至 79 岁年龄组运动单位放电行为的所有三个因素表明，可能用较大的运动单位替代通常在低张力下活跃的较小的运动单位。
The purpose of this study was to determine and compare the discharge characteristics of single motor-unit action potentials (SMUAPs) in young and aged subjects during 5, 10, and 20 percent of maximum voluntary contraction (MVC) of the abductor digiti minimi manus muscle. Three decades of aged subjects ranging from 60 to 90 years of age were compared with a group of 20 to 35 year olds. Specially constructed fine-wire bifilar recording electrodes were used, and SMUAPs were identified by interactive computer processing. Although the results did not reach a statistically significant level, they showed the 70- to 79-year-old age group had the longest mean interspike intervals (ISI) in each of the three percentages of MVC. The prolonged ISI indicate a slow motor-unit discharge rate. In addition, the 70- to 79-year-old group had a statistically significant floating standard deviation, indicating increased variability of discharge, and a significantly different negative floating serial correlation coefficient. All three factors describing motor-unit discharge behavior in the 70- to 79-year-old age group suggest possible substitution of larger motor units for smaller motor units normally active at low tensions.