Neural Engineering Research Laboratory, Department of Biomedical Engineering, School of Electrical and Computer Engineering, University of Campinas, Av. Albert Einstein, 400, Office 228, Building A., Cidade Universitaria Zeferino Vaz, Campinas, SP, 13083-852, Brazil.
Cellular and Structural Biology Graduate Program, Institute of Biology, University of Campinas, Campinas, SP, Brazil.
Med Biol Eng Comput. 2019 Aug;57(8):1813-1822. doi: 10.1007/s11517-019-01999-8. Epub 2019 Jun 14.
Studies have reported the benefits of sensory noise in motor performance, but it is not clear if this phenomenon is influenced by muscle contraction intensity. Additionally, most of the studies investigated the role of a stochastic noise on the improvement of motor control and there is no evidence that a sinusoidal vibrotactile stimulation could also enhance motor performance. Eleven participants performed a sensorimotor task while sinusoidal vibrations were applied to the finger skin. The effects of an optimal vibration (OV) on force steadiness were evaluated in different contraction intensities. We assessed the standard deviation (SD) and coefficient of variation (CoV) of force signals. OV significantly decreased force SD irrespective of contraction intensity, but the decrease in force CoV was significantly higher for low-intensity contraction. To the best of our knowledge, our findings are the first evidence that sinusoidal vibrotactile stimulation can enhance force steadiness in a motor task. Also, the significant improvement caused by OV during low-intensity contractions is probably due to the higher sensitivity of the motor system to the synaptic noise. These results add to the current knowledge on the effects of vibrotactile stimulation in motor control and have potential implications for the development of wearable haptic devices. Graphical abstract In this work the effects of a sinusoidal vibrotactile stimulation on force steadiness was investigated. Index finger sensorimotor tasks were performed in three levels of isometric contraction of the FDI muscle: 5, 10 and 15 %MVC. An optimal level of vibration significantly improved force steadiness, but the decrease in force CoV caused by vibration was more pronounced in contractions at 5 %MVC.
研究报告称，感觉噪声对运动表现有益，但目前尚不清楚这种现象是否受肌肉收缩强度的影响。此外，大多数研究都调查了随机噪声对运动控制改善的作用，而没有证据表明正弦振动触觉刺激也可以增强运动表现。11 名参与者在手指皮肤施加正弦振动时执行了一项感觉运动任务。在不同的收缩强度下评估了最佳振动（OV）对力稳定性的影响。我们评估了力信号的标准差（SD）和变异系数（CoV）。OV 显著降低了力 SD，而与收缩强度无关，但在低强度收缩时力 CoV 的降低幅度显著更高。据我们所知，我们的发现是首次证明正弦振动触觉刺激可以增强运动任务中的力稳定性的证据。此外，OV 在低强度收缩期间引起的显著改善可能是由于运动系统对突触噪声的更高敏感性。这些结果增加了关于振动触觉刺激对运动控制影响的现有知识，并对可穿戴触觉设备的发展具有潜在意义。 图摘要 在这项工作中，研究了正弦振动触觉刺激对力稳定性的影响。在三个食指屈肌等长收缩水平（5%、10%和 15%MVC）下进行了手指感觉运动任务。最佳振动水平显著提高了力稳定性，但振动引起的力 CoV 降低在 5%MVC 收缩时更为明显。
