Carteron Aude, McPartlan Kerry, Gioeli Christina, Reid Emily, Turturro Matt, Hahn Barry, Benson Cynthia, Zhang Wei
Department of Physical Therapy, College of Staten Island, City University of New York Staten Island, NY, USA.
Emergency Medicine, Staten Island University Hospital Staten Island, NY, USA.
Front Hum Neurosci. 2016 Nov 25;10:596. doi: 10.3389/fnhum.2016.00596. eCollection 2016.
Peripheral sensory feedback plays a crucial role in ensuring correct motor execution throughout hand grasp control. Previous studies utilized local anesthesia to deprive somatosensory feedback in the digits or hand, observations included sensorimotor deficits at both corticospinal and peripheral levels. However, the questions of how the disturbed and intact sensory input integrate and interact with each other to assist the motor program execution, and whether the motor coordination based on motor output variability between affected and non-affected elements (e.g., digits) becomes interfered by the local sensory deficiency, have not been answered. The current study aims to investigate the effect of peripheral deafferentation through digital nerve blocks at selective digits on motor performance and motor coordination in grasp control. Our results suggested that the absence of somatosensory information induced motor deficits in hand grasp control, as evidenced by reduced maximal force production ability in both local and non-local digits, impairment of force and moment control during object lift and hold, and attenuated motor synergies in stabilizing task performance variables, namely the tangential force and moment of force. These findings implied that individual sensory input is shared across all the digits and the disturbed signal from local sensory channel(s) has a more comprehensive impact on the process of the motor output execution in the sensorimotor integration process. Additionally, a feedback control mechanism with a sensation-based component resides in the formation process for the motor covariation structure.
在整个手部抓握控制过程中，外周感觉反馈对于确保正确的运动执行起着至关重要的作用。以往的研究利用局部麻醉来剥夺手指或手部的体感反馈，观察结果包括皮质脊髓和外周水平的感觉运动缺陷。然而，关于受干扰的和完整的感觉输入如何相互整合和相互作用以辅助运动程序执行的问题，以及基于受影响和未受影响的元素（如手指）之间运动输出变异性的运动协调是否会受到局部感觉缺陷的干扰，尚未得到解答。本研究旨在通过选择性手指的指神经阻滞来研究外周去传入对抓握控制中运动表现和运动协调的影响。我们的结果表明，体感信息的缺失会导致手部抓握控制出现运动缺陷，这表现为局部和非局部手指的最大力量产生能力降低、物体提起和握持过程中力量和力矩控制受损，以及稳定任务表现变量（即切向力和力矩）时运动协同作用减弱。这些发现意味着个体感觉输入在所有手指之间共享，并且来自局部感觉通道的干扰信号在感觉运动整合过程中对运动输出执行过程具有更全面的影响。此外，在运动共变结构的形成过程中存在一种基于感觉的反馈控制机制。
