Motor-unit coherence during isometric contractions is greater in a hand muscle of older adults.
Motor-unit coherence during isometric contractions is greater in a hand muscle of older adults.
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老年人的手部肌肉在等长收缩期间运动单位的一致性更强。
DOI：
10.1152/jn.00941.2002
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Enoka,RogerM
中科院分区：
文献类型：
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作者：
Semmler,JohnG;Kornatz,KurtW;Enoka,RogerM
本研究的目的是使用先前研究中获得的数据来量化年轻人和老年人第一背侧骨间肌运动单位一致性的强度，其中没有观察到两组之间运动单位同步性的差异。运动单元一致性的强度通过 11 名年轻人（年龄 24.1 ± 4.1 岁）的 47 个运动单元对和 14 名老年人（年龄 70.4 ± 5.9 岁）的 48 个运动单元对进行量化。老年人的运动单位一致性强度更强，特别是在 5-9 Hz 的低频下（老年人在 5 Hz 时高出 85%）。此外，老年人表现出大约 12-13 Hz 的额外振荡，而年轻受试者则没有这种振荡。这些数据表明，尽管共享输入（同步）的强度没有与年龄相关的差异，但老年人对运动神经元的常见振荡输入（运动单元一致性）增强。 此外，数据强调，运动单元同步和一致性的测量突出了同一共同输入的不同特征，并且一致性分析可能是表征运动神经元共享输入的更灵敏的工具。
The purpose of this study was to quantify the strength of motor-unit coherence from the first dorsal interosseus muscle in young and old adults using data obtained in a previous study, where no differences in motor-unit synchronization between the two groups were observed. The strength of motor-unit coherence was quantified from 47 motor-unit pairs in 11 young adults (age 24.1 ± 4.1 yrs) and from 48 motor-unit pairs in 14 old adults (age 70.4 ± 5.9 yrs). The strength of motor-unit coherence was greater in old adults, particularly at low frequencies of 5–9 Hz (85% greater in old adults at 5 Hz). In addition, the older adults expressed an extra oscillation at approximately 12–13 Hz that was not present in the young subjects. These data demonstrate that common oscillatory inputs to motor neurons (motor-unit coherence) are enhanced in older adults despite no age-related difference in the strength of shared inputs (synchronization). Furthermore, the data emphasize that measures of motor-unit synchronization and coherence highlight different features of the same common input, and a coherence analysis may be a more sensitive tool to characterize shared input to motor neurons.