Buneo C A, Soechting J F, Flanders M
Department of Physiology, University of Minnesota, Minneapolis, Minnesota 55455, USA.
J Neurosci. 1997 Mar 15;17(6):2128-42. doi: 10.1523/JNEUROSCI.17-06-02128.1997.
The neural control of reaching entails the specification of a precise pattern of muscle activation distributed across the many muscles of the arm. Musculoskeletal geometry limits the possible solutions to this problem. Insight into the nature of this constraint was obtained by quantifying the postural variation in the mechanical actions of six human shoulder muscles. Estimates of muscle mechanical actions were obtained by electrically stimulating muscles to the point of contraction and recording the resulting forces and torques with a six-degree-of-freedom force-torque transducer. In a given experiment, data were obtained for up to 29 different arm postures. The mechanical actions of each muscle varied systematically with arm posture, regardless of the frame of reference used to define these actions. The nature of this dependence suggests that a relatively simple strategy can be used by the nervous system to account for the changing mechanical actions of arm muscles.
手臂伸展的神经控制需要精确指定一种肌肉激活模式，该模式分布于手臂的众多肌肉中。肌肉骨骼几何学限制了这个问题的可能解决方案。通过量化六块人类肩部肌肉机械作用中的姿势变化，我们得以深入了解这种限制的本质。肌肉机械作用的估计值是通过电刺激肌肉直至收缩，并使用六自由度力-扭矩传感器记录由此产生的力和扭矩而获得的。在给定的实验中，最多可获取29种不同手臂姿势的数据。无论用于定义这些作用的参考系如何，每块肌肉的机械作用都随手臂姿势而系统地变化。这种依赖性的本质表明，神经系统可以使用一种相对简单的策略来解释手臂肌肉不断变化的机械作用。
