Assessing altered motor unit recruitment patterns in paretic muscles of stroke survivors using surface electromyography.
Assessing altered motor unit recruitment patterns in paretic muscles of stroke survivors using surface electromyography.
复制标题
DOI：
10.1088/1741-2560/12/6/066001
复制
发表时间：
2015-12
影响因子：
4
通讯作者：
Suresh NL
中科院分区：
文献类型：
--
作者：
Hu X;Suresh AK;Rymer WZ;Suresh NL
表面肌电图 (sEMG) 记录和信号处理技术的进步使我们能够非侵入性地表征大量运动单位 (MU) 的募集特性。在此，我们试图确定半球中风幸存者的麻痹肌中 MU 募集特性是否发生改变。使用先进的 EMG 传感器阵列，我们记录了中风幸存者的麻痹和对侧肌肉在第一背侧骨间肌等长收缩期间的 sEMG，其收缩水平范围为最大收缩值的 20% 至 60%。使用 MU 分解技术，可以导出每次等长收缩中同时激活的 MU 的 MU 动作电位幅度和募集阈值。我们的结果表明，瘫痪肌肉的募集组织受到显着破坏，因为描述募集等级顺序的大小原则被严重扭曲。 MU 是在非常狭窄的兵力范围内招募的，随着兵力输出的增加，当参考招募兵力大小时，产生了很强的集群效应。 MU 特性的此类干扰也与随意力产生的损害密切相关。我们的研究结果提供了关于中风幸存者偏瘫肌肉 MU 募集改变的直接证据，并表明这些改变可能导致自主收缩无力。
The advancement of surface electromyogram (sEMG) recording and signal processing techniques has allowed us to characterize the recruitment properties of a substantial population of motor units (MUs) non-invasively. Here we seek to determine whether MU recruitment properties are modified in paretic muscles of hemispheric stroke survivors. Using an advanced EMG sensor array, we recorded sEMG during isometric contractions of the first dorsal interosseous muscle over a range of contraction levels, from 20% to 60% of maximum, in both paretic and contralateral muscles of stroke survivors. Using MU decomposition techniques, MU action potential amplitudes and recruitment thresholds were derived for simultaneously activated MUs in each isometric contraction. Our results show a significant disruption of recruitment organization in paretic muscles, in that the size principle describing recruitment rank order was materially distorted. MUs were recruited over a very narrow force range with increasing force output, generating a strong clustering effect, when referenced to recruitment force magnitude. Such disturbances in MU properties also correlated well with the impairment of voluntary force generation. Our findings provide direct evidence regarding MU recruitment modifications in paretic muscles of stroke survivors, and suggest that these modifications may contribute to weakness for voluntary contractions.