Smeets Jeroen B J, Brenner Eli
Department of Human Movement Sciences, VU University Amsterdam, van der Boechorststraat 9, 1081, Amsterdam, BT, The Netherlands.
Adv Exp Med Biol. 2016;957:21-34. doi: 10.1007/978-3-319-47313-0_2.
The reach-to-grasp movement is a prototype of human movement coordination. Since the pioneering work of Jeannerod (Attention and performance, ix. Erlbaum, Hillsdale, NJ, pp 153-169, 1981), this movement is generally considered to be a coordinated combination of hand transport and grip formation. One of the main theoretical reasons for choosing transport and grip as building blocks is that they are anatomically independent: one can determine for each muscle, joint or brain area whether it belongs to transport or grip. We have proposed a different view on grasping, in which the coordination problem is formulated as one related to the movements of the digits (Smeets and Brenner in Motor Control 3:237-271, 1999). According to this view, both the transport of the hand and the formation of the grip emerge from the combination of independent digits' movements towards the objects' surface. This independency of the digits resembles the independence of synergies (as discussed in the chapter of d'Avella). Different synergies are activated independently, but a single muscle can be part of several synergies. In this chapter we will present three types of experiments that were designed to test to what extent the individual digits' movements can be considered the building blocks of the reach-to-grasp movement.
伸手抓握动作是人类运动协调的一个典型例子。自让诺罗德的开创性研究（《注意力与表现》，第九卷。埃尔布拉姆出版社，新泽西州希尔斯代尔，第153 - 169页，1981年）以来，这个动作通常被认为是手部运输和抓握形成的协调组合。选择运输和抓握作为基本组成部分的一个主要理论原因是它们在解剖学上是独立的：对于每一块肌肉、关节或脑区，都可以确定它属于运输还是抓握。我们对抓握提出了一种不同的观点，即把协调问题表述为与手指运动相关的问题（斯米茨和布伦纳，《运动控制》3:237 - 271，1999年）。根据这种观点，手部的运输和抓握的形成都源于各个独立手指向物体表面运动的组合。手指的这种独立性类似于协同作用的独立性（如在达韦拉的章节中所讨论的）。不同的协同作用是独立激活的，但一块肌肉可以是几种协同作用的一部分。在本章中，我们将介绍三种类型的实验，这些实验旨在测试各个手指的运动在多大程度上可以被视为伸手抓握动作的基本组成部分。
