Effects of object compliance on three-digit grasping.
Effects of object compliance on three-digit grasping.
复制标题
物体顺应性对三位数抓取的影响。
DOI：
10.1152/jn.91021.2008
复制
发表时间：
2009
影响因子：
2.5
通讯作者：
Flanders,Martha
中科院分区：
文献类型：
--
作者：
Winges,SaraA;Eonta,StephanieE;Soechting,JohnF;Flanders,Martha
与刚性物体相比，抓取和提升柔性物体存在额外的不确定性。对于任何静态抓握，指尖处的力取决于包括接触点的位置在内的因素，并且接触力必须协调以保持平衡。对于柔性物体，接触表面的位置和方向以力相关的方式改变，从而改变力要求。此外，每次力调整都会导致物体形状的额外变化。这项研究的特点是在这种情况下的力量和肌肉激活模式。指尖的力量被测量为受试者抓住，并提出了200克的物体，用他们的拇指，食指和无名指。有时在食指和/或无名指接触表面下放置弹簧。记录了10块手部肌肉和1块臂近端肌肉的表面肌电活动。在负荷和提升阶段，抓握（正常）力和肌肉活动的模式在各种条件下相似，但其幅度取决于接触表面是否柔顺。具体而言，在所有条件下，在任务的负荷阶段，握力平稳增加。相反，当一个或多个接触表面顺应时，切向接触（负载）力不会单调增加，导致夹持力和负载力解耦。
Compared with rigid objects, grasping and lifting compliant objects presents additional uncertainties. For any static grasp, forces at the fingertips depend on factors including the locations of the contact points and the contact forces must be coordinated to maintain equilibrium. For compliant objects, the locations and orientations of the contact surfaces change in a force-dependent manner, thus changing the force requirements. Furthermore, every force adjustment then results in additional changes in object shape. This study characterized force and muscle activation patterns in this situation. Fingertip forces were measured as subjects grasped and lifted a 200-g object using their thumb, index, and ring fingers. A spring was sometimes placed under the index and/or ring finger contact surface. Surface electromyographic activity was recorded from ten hand muscles and one proximal arm muscle. The patterns of grip (normal) force and muscle activity were similar across conditions during the load and lift phases, but their amplitude depended on whether the contact surface was compliant. Specifically, the grip force increased smoothly during the load phase of the task under all conditions. To the contrary, the tangential contact (load) force did not increase monotonically when one or more of the contact surfaces were compliant, resulting in a decoupling of the grip and load forces.