Dynamics of wrist rotations
Dynamics of wrist rotations
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DOI：
10.1016/j.jbiomech.2010.11.016
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发表时间：
2011-02-24
影响因子：
2.4
通讯作者：
Hogan, Neville
中科院分区：
文献类型：
--
作者：
Charles, Steven K.;Hogan, Neville
了解手腕旋转的动力学对许多领域都很重要，包括生物力学、康复和运动神经科学。建立了腕关节在屈伸(FE)和尺偏(RUD)状态下的旋转动力学数学模型，描述了克服腕关节被动机械阻抗所需的力矩。手绕手腕关节旋转的运动方程包括惯性项、阻尼项和刚度项，参数值基于直接测量(刚度)或与文献中提供的数据相结合的测量(惯性、阻尼)。我们测量了六名年轻、健康的受试者的手腕运动学，这些受试者进行了舒适的快节奏手腕旋转(FE、RUD和组合中的+/-15度)，并将这些运动学数据插入到手腕旋转动力学模型中。在此基础上，我们量化了克服手腕旋转阻抗所需的扭矩，并评估了各个阻抗项的相对重要性以及自由度之间的相互作用。我们发现，手腕的被动僵硬是神经肌肉系统旋转手腕必须克服的主要阻抗。只有在非常快的动作中，惯性和被动减震才变得重要。与肘部和肩部的伸展运动不同，惯性相互作用力矩对于手腕旋转可以忽略不计。然而，由于刚度和阻尼而产生的相互作用力矩是显著的。最后，我们发现一些模型项(惯性相互作用力矩、轴偏移量和，对于中等大小的旋转)。非线性)可以忽略不计，精确度损失很小，得到一个简单的线性模型，可用于生物力学、运动神经科学和康复方面的研究。(C)2010爱思唯尔有限公司。保留所有权利。
Understanding the dynamics of wrist rotations is important for many fields, including biomechanics, rehabilitation and motor neuroscience. This paper provides an experimentally based mathematical model of wrist rotation dynamics in Flexion-Extension (FE) and Radial-Ulnar Deviation (RUD), and characterizes the torques required to overcome the passive mechanical impedance of wrist rotations.We modeled the wrist as a universal joint with non-intersecting axes. The equations of motion of the hand rotating about the wrist joint include inertial, damping, and stiffness terms, with parameter values based on direct measurements (stiffness) or measurements combined with data available in the literature (inertia, damping). We measured the wrist kinematics of six young, healthy subjects making comfortable and fast-paced wrist rotations (+/-15 degrees in FE, RUD, and combinations) and inserted these kinematic data into the model of wrist rotation dynamics. With this we quantified the torques required to overcome the impedance of wrist rotations and evaluated the relative importance of individual impedance terms as well as interactions between the degrees of freedom.We found that the wrist's passive stiffness is the major impedance the neuromuscular system must overcome to rotate the wrist. Inertia and passive damping only become important for very fast movements. Unlike elbow and shoulder reaching movements, inertial interaction torques are negligible for wrist rotations. Interaction torques due to stiffness and damping, however, are significant. Finally, we found that some model terms (inertial interaction torques, axis offset, and, for moderately sized rotations. non-linearities) can be neglected with little loss of accuracy, resulting in a simple, linear model useful for studies in biomechanics, motor neuroscience, and rehabilitation. (C) 2010 Elsevier Ltd. All rights reserved.