Influence of biomechanical factors on substructure of pointing movements
Influence of biomechanical factors on substructure of pointing movements
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DOI：
10.1007/s00221-005-2271-4
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发表时间：
2005-08-01
影响因子：
2
通讯作者：
Johnson, T
中科院分区：
文献类型：
--
作者：
Dounskaia, N;Wisleder, D;Johnson, T
指向运动结束时速度分布的不规则性被解释为校正子运动，其目的是提供指向目标的准确性。本研究的目的是调查与手臂生物力学特性相关的两个额外因素是否也会导致运动不足。首先，离散指向任务所需的肢体运动终止和稳定在最终位置可能有助于子运动。其次，关节处交互扭矩的不准确调节也可能导致子运动。为了研究这两个生物力学因素和传统上考虑的指向精度因素的贡献，分析了三种类型的实验操作期间的子运动发生率。除了目标尺寸操纵（小目标和大目标）之外，还通过检查离散运动（在目标处终止）和往复运动（在不停留在目标上的情况下反转方向）来操纵运动终止条件。通过使用需要不同肩肘协调模式的目标来改变交互扭矩。在所有分析的运动中，有 41% 检测到了子运动。数据支持精度和运动终止因素的影响，但不支持交互扭矩调节因素对次运动发生率的影响。粗大的轻微运动与运动终止有关；精细的子运动主要满足精度要求。这些发现和对时间运动特征的分析表明，运动终止是一种额外的运动成分，使得离散运动的控制不同于往复运动的控制。讨论了研究结果对菲茨定律与噪声相关的解释的影响。该研究强调了手臂生物力学对端点运动学的影响。
Irregularities in the velocity profile near the end of pointing movements have been interpreted as corrective submovements whose purpose is to provide accuracy of pointing to the target. The purpose of the present study was to investigate whether two additional factors related to biomechanical properties of the arm also cause submovements. First, motion termination and stabilization of the limb in the final position required by a discrete pointing task may contribute to submovements. Second, inaccurate regulation of interactive torque at the joints may also cause submovements. To investigate the contributions of these two biomechanical factors and the traditionally considered factor of pointing accuracy, the incidence of submovements was analyzed during three types of experimental manipulations. In addition to target size manipulations (small and large targets), conditions for motion termination were manipulated by examining discrete movements (which terminated at the target) and reciprocal movements (which reversed direction without dwelling on the target). Interaction torques were varied by using targets that require different shoulder-elbow coordination patterns. Submovements were detected in 41% of all analyzed movements. Data supported influences from the accuracy and motion termination factors but not from the interactive torque regulation factor on submovement incidence. Gross submovements were associated with motion termination; fine submovements primarily with accuracy demands. These findings and the analysis of temporal movement characteristics suggest that motion termination is an extra movement component that makes control of discrete movements different to control of reciprocal movements. Implications of the findings to a noise-related interpretation of Fitts' law are discussed. The study emphasizes the influence of arm biomechanics on endpoint kinematics.