Effect of Object Width on Muscle and Joint Forces During Thumb-Index Finger Grasping
Effect of Object Width on Muscle and Joint Forces During Thumb-Index Finger Grasping
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DOI：
10.1123/jab.27.3.173
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发表时间：
2011-08-01
影响因子：
1.4
通讯作者：
Berton, Eric
中科院分区：
文献类型：
--
作者：
Vigouroux, Laurent;Domalain, Mathieu;Berton, Eric
这项研究的目的是确定改变物体宽度对握持物体时肌肉和关节力的影响。实验方案包括用拇指-食指握持水平保持五个不同宽度的物体(3.5、4.5、5.5、6.5和7.5厘米)。受试者被要求自发地抓住物体，而没有任何关于要施加的握力(GF)的指示。建立了拇指-食指夹持的生物力学模型，用于估计肌肉和关节的作用力。该模型包括肌电、指尖力和运动学数据作为输入。手指关节姿势和GF随对象宽度的不同而不同。估计的肌肉力量也因物体宽度的不同而显著不同。有趣的是，我们观察到，主要屈肌的肌力/生长因子比率在宽度方面保持特别稳定，而其他肌肉比率差异很大。这可能需要一种控制策略，在这种策略中，尽管关节姿势发生变化，屈肌的动作仍然保持不变。估计的联合力随着物体宽度的增加而增加，并在远-近端感觉上增加。总体而言，这些结果对于手持式对象的人体工学设计和临床应用具有重要意义。
The objective of this study was to identify the impact of modifying the object width on muscle and joint forces while gripping objects. The experimental protocol consisted to maintain horizontally five objects of different widths (3.5, 4.5, 5.5, 6.5, and 7.5 cm) with a thumb-index finger grip. Subjects were required to grasp spontaneously the object without any instruction regarding the grip force (GF) to apply. A biomechanical model of thumb-index finger pinch was developed to estimate muscle and joint forces. This model included electromyography, fingertip force, and kinematics data as inputs. The finger joint postures and the GF varied across the object widths. The estimated muscle forces also varied significantly according to the object width. Interestingly, we observed that the muscle force/GF ratios of major flexor muscles remain particularly stable with respect to the width whereas other muscle ratios differed largely. This may argue for a control strategy in which the actions of flexors were preserved in spite of change in joint postures. The estimated joint forces tended to increase with object width and increased in the distal-proximal sense. Overall, these results are of importance for the ergonomic design of handheld objects and for clinical applications.