Rougier Patrice R, Boudrahem Samir
Laboratoire interdisciplinaire de biologie de la motricité, université de Savoie- Mont Blanc, domaine scientifique de Savoie-Technolac, 73376 le Bourget du Lac cedex, France.
Laboratoire interdisciplinaire de biologie de la motricité, université de Savoie- Mont Blanc, domaine scientifique de Savoie-Technolac, 73376 le Bourget du Lac cedex, France.
Neurophysiol Clin. 2017 Sep;47(4):305-314. doi: 10.1016/j.neucli.2017.01.010. Epub 2017 Mar 15.
The technique of additional visual feedback has been shown to significantly decrease the center of pressure (CP) displacements of a standing subject. Body-weight asymmetry is known to increase postural instability due to difficulties in coordinating the reaction forces exerted under each foot and is often a cardinal feature of various neurological and traumatic diseases. To examine the possible interactions between additional visual feedback and body-weight asymmetry effects, healthy adults were recruited in a protocol with and without additional visual feedback, with different levels of body-weight asymmetry.
CP displacements under each foot were recorded and used to compute the resultant CP displacements (CP) and to estimate vertically projected center of gravity (CG) and CP-CG displacements. Overall, six conditions were randomly proposed combining two factors: asymmetry with three BW percentage distributions (50/50, 35/65 and 20/80; left/right leg) and feedback (with or without additional VFB).
The additional visual feedback technique principally reduces CG displacements, whereas asymmetry increases CP-CG displacements along the mediolateral axis. Some effects on plantar CP displacements were also observed, but only under the unloaded foot. Interestingly, no interaction between additional visual feedback and body-weight asymmetry was reported.
These results suggest that the various postural effects that ensue from manipulating additional visual feedback parameters, shown previously in healthy subjects in various studies, could also apply independently of the level of asymmetry.
Visual feedback effects could be observed in patients presenting weight-bearing asymmetries.
额外视觉反馈技术已被证明能显著减少站立受试者的压力中心（CP）位移。众所周知，体重不对称会增加姿势不稳定，因为难以协调每只脚下施加的反作用力，而且它通常是各种神经和创伤性疾病的主要特征。为了研究额外视觉反馈与体重不对称效应之间可能的相互作用，我们招募了健康成年人参与一项实验，实验设置了有和没有额外视觉反馈、不同体重不对称水平的方案。
记录每只脚下的CP位移，用于计算合成CP位移（CP），并估计垂直投影重心（CG）和CP - CG位移。总体而言，随机提出了六种条件，结合了两个因素：不对称，有三种体重百分比分布（50/50、35/65和20/80；左腿/右腿）和反馈（有或没有额外视觉反馈）。
额外视觉反馈技术主要减少CG位移，而不对称会增加沿内外侧轴的CP - CG位移。还观察到对足底CP位移有一些影响，但仅在无负荷的脚下。有趣的是，未报告额外视觉反馈与体重不对称之间存在相互作用。
这些结果表明，先前在各种研究中的健康受试者身上所显示的，通过操纵额外视觉反馈参数产生的各种姿势效应，也可能独立于不对称水平而适用。
在存在负重不对称的患者中可以观察到视觉反馈效应。
