Commonalities and differences in control of various drawing movements
Commonalities and differences in control of various drawing movements
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DOI：
10.1007/s00221-002-1144-3
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发表时间：
2002-09-01
影响因子：
2
通讯作者：
Stelmach, GE
中科院分区：
文献类型：
--
作者：
Dounskaia, N;Ketcham, CJ;Stelmach, GE
本文研究了九种绘画动作中肩肘关节的控制特点。该任务是重复跟踪模板，描绘在水平表上，用食指在1.5 Hz的循环频率。模板是一个圆形，四个椭圆形和四条不同方向的线。手腕被固定，运动包括肩关节和肘关节的旋转。所研究的运动在很大范围内变化，肘和肩运动的幅度和它们之间的相对相位。动力学分析包括扭矩信号、脉冲和时间的分析。这表明，肌肉扭矩在运动产生中的作用在两个关节是不同的。在八出的九个运动类型，在肩部的肌肉扭矩加速和减速这个关节，几乎完全应付的影响，肘关节运动所产生的相互作用的扭矩。相反，由肩部运动产生的交互扭矩在肘部加速和减速中起主导作用，而手肘的肌肉扭矩将被动肘部运动调整为各种模板形状。肌电图数据与动力学分析的结论一致。总的来说，这些数据支持这两个关节在运动产生中具有不同功能的假设。肩部通过交互扭矩为整个手臂的运动创建基础，手肘用作端点运动的微调器。在这八种运动类型中，肩部的控制是相似的，肘部控制的变化提供了终点路径的差异。两个关节在一个动作类型中交换角色，即向右倾斜画线。在此运动期间，手肘肌肉组织在该关节处产生运动，而肩部肌肉组织抵消了该运动对肩部位置的机械影响。研究结果表明，在绘画运动中，控制策略利用段间动态的肩肘机械联动。
Characteristics of control at the shoulder and elbow during nine types of drawing movements were studied in the present work. The task was to repetitively track a template, depicted on a horizontal table, with the index finger at a cyclic frequency of 1.5 Hz. The templates were a circle, four ovals and four lines of different orientations. The wrist was immobilized and the movement consisted of rotations at the shoulder and elbow joints. The studied movements varied in a wide range with respect to the amplitude of elbow and shoulder movements and relative phase between them. Kinetic analysis included analysis of torque signs, impulses, and timing. It demonstrated that the role of muscle torque in movement production was different at the two joints. During eight out of the nine movement types, the muscle torque at the shoulder accelerated and decelerated this joint and almost completely coped with the influence of the interactive torque arising from elbow motion. Conversely, interactive torque generated by shoulder motion played a dominant role in elbow acceleration and deceleration, whereas muscle torque at the elbow adjusted passive elbow movement to the various template shapes. EMG data were in agreement with the conclusions made from the kinetic analysis. Collectively, these data support the hypothesis that the two joints have different functions in movement production. The shoulder creates a foundation for motion of the entire arm through the interactive torque, and the elbow serves as a fine-tuner of the endpoint movement. Control of the shoulder was similar across the eight movement types and the differences in the end-point path were provided by variations in elbow control. The two joints exchanged roles during one movement type, namely, drawing the line tilted right. During this movement, the elbow musculature generated motion at this joint and the shoulder musculature counteracted mechanical influence of this motion on the shoulder position. The findings suggest that during drawing movements, the control strategy exploits intersegmental dynamics of the shoulder-elbow mechanical linkage.