Christel Marianne I, Billard Aude
Institut fur Spezielle Zoologie und Evolutionsbiologie, Friedrich-Schiller-Universitaet, Erbertstrasse 1, D-07743, Jena, Germany.
Behav Brain Res. 2002 Apr 1;131(1-2):169-84. doi: 10.1016/s0166-4328(01)00372-2.
Reaching and grasping has been widely studied in both macaques and humans, mainly with the aim of finding similar patterns of behavior in the two species. Little attention has yet been given to how morphological and behavioral differences between the two species might affect the kinematics of the movement. In this study, we present a careful analysis of the similarities and differences between humans' and macaques' prehension movements and discuss these with respect to both the control system and the biomechanics of the arm. Five humans and five macaques performed the same task, namely grasping small feeding objects using a precision grip. Macaques were observed in unconstrained conditions, free to adjust their body posture. The behavioral protocol for macaques revealed a postural preference for sitting and keeping the elbow slightly flexed when applying a precision grip. In agreement with the literature, kinematics revealed general features of movement common to both humans and macaques. However, within a similar timeframe, macaques produced steeper and wider excursion of the elbow and of the wrist, smaller abduction of the shoulder joint and larger displacement of the torso than humans did. The three-joint limb revealed stronger irregularities for the macaques. We hypothesize that the larger kinematic irregularities and the specific elbow--shoulder posture in macaques result in part from an effort of the control system to compensate for different biomechanical constraints, namely for limited shoulder-joint excursion, in order to achieve a similar range of comfort of motion. Finally, we briefly consider the influence of primitive neural circuits responsible for arm motion during locomotion and speculated on their influence on the control of reaching in macaques.
在猕猴和人类中，伸手抓取动作已得到广泛研究，主要目的是探寻这两个物种中相似的行为模式。然而，对于这两个物种在形态和行为上的差异如何影响运动的运动学，人们关注甚少。在本研究中，我们仔细分析了人类和猕猴抓握动作的异同，并从控制系统和手臂生物力学的角度进行了讨论。五名人类受试者和五只猕猴执行了相同的任务，即使用精确抓握方式抓取小的喂食物体。猕猴在无约束条件下接受观察，可以自由调整身体姿势。针对猕猴的行为记录显示，在进行精确抓握时，它们在姿势上偏好坐姿并保持肘部微屈。与文献一致，运动学研究揭示了人类和猕猴运动的共同特征。然而，在相似的时间范围内，猕猴肘部和腕部的伸展幅度更大、更陡，肩关节外展幅度更小，躯干位移比人类更大。对于猕猴而言，三关节肢体显示出更强的不规则性。我们推测，猕猴较大的运动学不规则性以及特定的肘部 - 肩部姿势，部分是由于控制系统努力补偿不同的生物力学限制，即有限的肩关节活动范围，以实现类似的舒适运动范围。最后，我们简要考虑了负责运动过程中手臂运动的原始神经回路的影响，并推测了它们对猕猴伸手动作控制的影响。
