Sitting balance I: trunk-arm coordination and the contribution of the lower limbs during self-paced reaching in sitting
Sitting balance I: trunk-arm coordination and the contribution of the lower limbs during self-paced reaching in sitting
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DOI：
10.1016/s0966-6362(99)00026-0
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发表时间：
1999-10-01
期刊：
影响因子：
2.4
通讯作者：
Adams, R
中科院分区：
文献类型：
--
作者：
Dean, C;Shepherd, R;Adams, R
研究了动作距离和任务类型对坐姿自主动作中躯干、上肢和下肢功能关系的影响。6名健康受试者在3个距离（60,100,140%臂长）和2个任务（伸手按下开关）下向前伸展时，采集二维运动学、动力学和肌电图（EMG）数据。伸手去抓玻璃)条件。结果表明，任务类型主要影响协调的时间方面，抓取任务持续比按压任务更长。而到达距离对躯干与臂段协调的时空影响和下肢的主动贡献均有影响。随着到达距离的增加，躯干和上臂节段运动的幅度增大，而前臂节段运动的幅度减小。然而，在每个到达距离，手的路径是相对笔直的，并且在受试者内部和受试者之间躯干和手臂段之间的关系有显著的一致性，这表明尽管存在冗余自由度，个体使用的是一种简约的协调模式。垂直地面反作用力（GRF）和肌电图数据表明，当物体位于手臂长度的140%时，下肢积极贡献支撑身体质量。(C) 1999 Elsevier Science B.V.版权所有
The effects of reach distance and type of task on the functional relationship between the trunk, upper limb segments and the lower limbs juring self-paced reaching in sitting were examined. Two-dimensional kinematic, kinetic and electromyography (EMG) data were collected as six healthy subjects reached forward under three distance (60, 100, 140% arm's length) and two task (reaching to press a switch. reaching to grasp a glass) conditions. The results demonstrate that type of task affected primarily the temporal aspects of coordination, with the grasp task taking consistently longer than the press task. In contrast, reach distance affected both the spatio-temporal aspects of coordination between the trunk and arm segments and the active contribution of the lower limbs. As reach distance increased, the magnitude of trunk and upper-arm segmental motion increased, whereas forearm segmental motion decreased. However, at each reach distance the path of the hand was relatively straight and there was remarkable consistency in the relationship between trunk and arm segments both within and between subjects suggesting that despite the presence of redundant degrees of freedom, the individual uses a parsimonious coordinative pattern. The vertical ground reaction force (GRF) and EMG data demonstrated that the lower limbs actively contributed to support the body mass when the object was located at 140% arm's length. (C) 1999 Elsevier Science B.V. All rights reserved.