MYOELECTRIC RESPONSE OF BACK MUSCLES TO VERTICAL RANDOM WHOLE-BODY VIBRATION WITH DIFFERENT MAGNITUDES AT DIFFERENT POSTURES
MYOELECTRIC RESPONSE OF BACK MUSCLES TO VERTICAL RANDOM WHOLE-BODY VIBRATION WITH DIFFERENT MAGNITUDES AT DIFFERENT POSTURES
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DOI：
10.1006/jsvi.2001.4248
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发表时间：
2002-05
影响因子：
4.7
通讯作者：
R. Blüthner;H. Seidel;B. Hinz
中科院分区：
文献类型：
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作者：
R. Blüthner;H. Seidel;B. Hinz
背部肌肉力量对全身振动引起的脊柱负荷有重要贡献。肌电图（EMG）可以帮助估计这些力量在全身振动（WBV）。38名受试者暴露于相同的随机低频WBV（0·7、1·0和1·4 m/s-2 r.m.s.）。加权加速度）在放松，直立和向前弯曲的姿势。测量了座椅的加速度和座椅与臀部之间的力。6个肌电信号来自右侧的m。下降部，m.胸回肋腰肌腰回肋肌腰部;胸最长肌胸最长肌腰段和腰多裂肌。对所有数据进行滤波以进行抗混叠，并以1000 Hz进行采样。利用小波变换在时域中识别和消除了ECG在EMG中引起的伪影。个体校正和标准化的EMG在受试者中平均。没有WBV的肌电图表现出的三个姿势检查的特征模式。的连贯性和传递函数表示特征肌电反应随机WBV的姿势和WBV幅度的几个影响。提出了一套从座椅加速度或平均归一化输入力到平均处理后肌电信号的综合传递函数。研究结果可用于开发更复杂的模型，并单独控制各种背部肌肉群。然而，在动态条件下的肌电-力的关系需要更详细地检查，然后才能实施的结果。由于取决于WBV频率的不同反射机制与不同类型的活动肌纤维相关联，因此可能需要EMG和肌肉力量之间的各种时间延迟。
Abstract Back muscle forces contribute essentially to the whole-body vibration-induced spinal load. The electromyogram (EMG) can help to estimate these forces during whole-body vibration (WBV). Thirty-eight subjects were exposed to identical random low-frequency WBV (0·7, 1·0 and 1·4 m/s -2 r.m.s. weighted acceleration) at a relaxed, erect and bent forward postures. The acceleration of the seat and the force between the seat and the buttocks were measured. Six EMGs were derived from the right side of the m. trapezius pars descendens, m. ileocostalis lumborum pars thoracis, m. ileocostalis lumborum pars lumborum; m. longissimus thoracis pars thoracis, m. longissimus thoracis pars lumborum, and lumbar multifidus muscle. All data were filtered for anti-aliasing and sampled with 1000 Hz. Artefacts caused by the ECG in the EMG were identified and eliminated in the time domain using wavelets. The individually rectified and normalized EMGs were averaged across subjects. The EMGs without WBV exhibited characteristic patterns for the three postures examined. The coherence and transfer functions indicated characteristic myoelectric responses to random WBV with several effects of posture and WBV magnitude. A comprehensive set of transfer functions from the seat acceleration or the mean normalized input force to the mean processed EMG was presented. The results can be used for the development of more sophisticated models with a separate control of various back muscle groups. However, the EMG–force relationship under dynamic conditions needs to be examined in more detail before the results can be implemented. Since different reflex mechanisms depending on the frequency of WBV are linked with different types of active muscle fibres, various time delays between the EMG and muscle force may be necessary.