咀嚼肌运动单位的三维幅度特征和提取运动单位样本的代表性。

Three-dimensional amplitude characteristics of masseter motor units and representativeness of extracted motor unit samples.

机构信息

Department of Orthodontics, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.

出版信息

Clin Neurophysiol. 2019 Mar;130(3):388-395. doi: 10.1016/j.clinph.2018.12.008. Epub 2019 Jan 19.

DOI:10.1016/j.clinph.2018.12.008

PMID:30708279

Abstract

OBJECTIVE

This study aimed to characterize amplitude topographies for masseter motor units (MUs) three-dimensionally, and to assess whether high-density surface electromyography (HDsEMG) is able to detect MU samples that represent the masseter's entire MU pool.

METHODS

Ten healthy adult volunteers participated in the study, which combined three EMG techniques. A HDsEMG grid covering the entire masseter, and intramuscular fine-wire electrodes were used to obtain two independent MU samples for comparison. The MUs' amplitude profiles in the dimension of muscle depth were determined using scanning EMG. All data were recorded simultaneously during a low, constant contraction level controlled by 3D force feedback.

RESULTS

The median medio-lateral diameter of 4.4 mm (range: 1.2-7.9 mm) for MUs detected by HDsEMG did not differ significantly (Mann-Whitney-U test, p = 0.805) from that of 3.9 mm (0.6-8.6 mm) for MUs detected by fine-wire EMG. For individual subjects, the medio-lateral diameters of all HDsEMG-detected MUs spanned 70.5% (19.2-75.1%) of the masseter's thickness.

CONCLUSIONS

HDsEMG is able to examine small and large MUs from a great masseter proportion in one single measurement.

SIGNIFICANCE

Clinical application of HDsEMG might contribute to a better understanding of neuromuscular adaptations in patients with temporomandibular disorders (TMD) and could allow for monitoring treatment effects.

摘要

目的

本研究旨在对咀嚼肌运动单位（MU）的三维幅度分布进行特征描述，并评估高密度表面肌电图（HDsEMG）是否能够检测到代表咀嚼肌整个 MU 池的 MU 样本。

方法

10 名健康成年志愿者参与了本研究，该研究结合了 3 种 EMG 技术。使用覆盖整个咀嚼肌的 HDsEMG 网格和肌内细电极获得两个独立的 MU 样本进行比较。使用扫描 EMG 确定 MU 在肌肉深度维度上的幅度分布。所有数据均在由 3D 力反馈控制的低恒定收缩水平下同时记录。

结果

HDsEMG 检测到的 MU 的中-外侧直径中位数为 4.4 mm（范围：1.2-7.9 mm），与细电极 EMG 检测到的 MU 的 3.9 mm（0.6-8.6 mm）无显著差异（Mann-Whitney-U 检验，p=0.805）。对于个别受试者，所有 HDsEMG 检测到的 MU 的中-外侧直径均跨越了咀嚼肌厚度的 70.5%（19.2-75.1%）。