Lee Beom-Chan, Ho Allison, Martin Bernard J, Sienko Kathleen H
Dept. of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2012;2012:6149-52. doi: 10.1109/EMBC.2012.6347397.
The purpose of this study was to characterize the effects of co-vibrotactile stimulations around the torso on non-volitional postural responses in the absence of instructions. Four healthy young adults maintained an upright, erect posture with their eyes closed in two different stance conditions: normal and Romberg stance. Six vibrotactile transducers (tactors) were placed on the skin over the right and left external oblique, internal oblique, and erector spinae muscles. Either a combination of vibration at two locations or all locations around the torso was applied for 5 s during each experimental trial. Regardless of stance condition, vibration applied concurrently over the right and left internal oblique muscle locations and the right and left erector spinae muscle locations induced a postural shift in the anterior and posterior directions, respectively. For these two stimulation conditions, the root-mean-square of sway in the anterior-posterior direction was significantly greater during vibration than before or after stimulation. However, simultaneous activation of all tactors, a combination of right internal oblique and right erector spinae locations, and a combination of left internal oblique and left erector spinae locations did not produce significant directional postural shifts or increases in sway, regardless of the stance condition. These findings suggest that stimuli combinations contribute to a vector summation of individual postural responses described in our previous work and that they could be leveraged in balance-related applications of sensory augmentation vibrotactile displays.
本研究的目的是在无指令的情况下，表征躯干周围协同振动触觉刺激对非自主姿势反应的影响。四名健康的年轻成年人在两种不同的站立条件下闭眼保持直立姿势：正常站立姿势和罗姆伯格姿势。六个振动触觉换能器（触觉器）放置在右侧和左侧腹外斜肌、腹内斜肌以及竖脊肌上方的皮肤上。在每次实验试验期间，对两个位置或躯干周围所有位置的振动组合施加5秒。无论站立条件如何，同时施加于右侧和左侧腹内斜肌位置以及右侧和左侧竖脊肌位置的振动分别引起前后方向的姿势偏移。对于这两种刺激条件，前后方向摇摆的均方根在振动期间显著大于刺激前或刺激后。然而，无论站立条件如何，所有触觉器同时激活、右侧腹内斜肌和右侧竖脊肌位置的组合以及左侧腹内斜肌和左侧竖脊肌位置的组合均未产生明显的方向性姿势偏移或摇摆增加。这些发现表明，刺激组合有助于我们之前工作中描述的个体姿势反应的矢量总和，并且它们可用于感觉增强振动触觉显示器的平衡相关应用中。
