Gallina Alessio, Vieira Taian
Laboratorio per l'Ingegneria del Sistema Nuromuscolare, Dipartimento di Ingegneria Elettronica, Politecnico di Torino, Via Cavalli 22/h, 10138, Torino, Italy.
Graduate Program in Rehabilitation Sciences, Department of Physical Therapy, University of British Columbia, Vancouver (BC), Canada.
Muscle Nerve. 2015 Dec;52(6):1057-65. doi: 10.1002/mus.24662. Epub 2015 Sep 8.
The aim of this study was to determine whether muscle fibers innervated by single motor neurons are confined in small subvolumes of the vastus medialis (VM) and if motor unit fiber orientation depends on their position within the muscle.
Single motor units were identified from a grid of surface electrodes. The size of their surface representation and fiber orientation were extracted using an algorithm validated on simulated signals.
The action potentials of 77 motor units were represented locally on the skin (10th-90th percentiles: 14-25 mm). According to simulations, this indicates territories smaller than 11.8-64.8 mm. Motor units in distal regions of VM had fibers at a greater angle than those in proximal regions (R = -0.54, P < 0.001).
Motor units with small territories and varying fiber orientations may be an anatomical predisposition to regulate how regions within VM apply forces to the patella. This could help to redistribute loads within the joint in painful conditions.
本研究的目的是确定由单个运动神经元支配的肌纤维是否局限于股内侧肌（VM）的小亚体积内，以及运动单位纤维的方向是否取决于它们在肌肉内的位置。
从表面电极网格中识别单个运动单位。使用在模拟信号上验证的算法提取其表面表征的大小和纤维方向。
77个运动单位的动作电位在皮肤上局部呈现（第10百分位数至第90百分位数：14 - 25毫米）。根据模拟，这表明区域小于11.8 - 64.8毫米。VM远端区域的运动单位纤维角度大于近端区域（R = -0.54，P < 0.001）。
具有小区域和不同纤维方向的运动单位可能是一种解剖学倾向，用于调节VM内区域如何向髌骨施加力。这有助于在疼痛情况下重新分配关节内的负荷。
