Laboratoire Interdisciplinaires de Biologie de la Motricité, EA 7424, Université de Savoie, Domaine Scientifique de Savoie-Technolac, 73376 Le Bourget du Lac cedex, France.
Laboratoire Interdisciplinaires de Biologie de la Motricité, EA 7424, Université de Savoie, Domaine Scientifique de Savoie-Technolac, 73376 Le Bourget du Lac cedex, France.
J Biomech. 2019 Jun 11;90:113-118. doi: 10.1016/j.jbiomech.2019.04.041. Epub 2019 May 4.
Both center-of-pressure (CP) displacements under each foot and relative body-weight distribution intervene in the production of resultant CP movements. To better understand their respective involvement, a protocol was set up for young healthy individuals consisting in standing on a double seesaw, favoring pitch motions and laying on a dual-force platform. The postural control effects induced by two types of asymmetry, weight-bearing and the CP movement patterns, were investigated. These asymmetries were achieved by associating two seesaws with two different lengths for the radii of the ridges and by requiring specific body-weight distributions. The results indicate that the postural strategies, aimed at controlling anteroposterior sway, are related to the subjects' capacity to minimize the CP displacements under the less stable support, whatever load is applied. In contrast, the degree of involvement of the more stable support must be viewed as a complement used to secure the appropriate motor output, i.e., the resultant CP movements. Within this objective, both the applied load and the CP amplitudes under the more stable support are taken into account. These data provide additional insights into the compensatory mechanisms between the interactions between the two feet, which are used to produce the adequate resultant CP movements and therefore upright stance control. The specificity of the double seesaw that can induce asymmetric CP patterns and/or asymmetric body-weight distribution makes it a legitimate contender to be used as a rehabilitation device for patients with neurological and/or traumatic diseases.
足底压力中心（CP）位移和身体相对重量分布都会影响合力 CP 运动的产生。为了更好地理解它们各自的作用，我们为年轻健康个体设计了一个方案，让他们站在一个双跷跷板上，以俯仰运动为主，并躺在一个双力平台上。该方案研究了两种不对称性（承重不对称和 CP 运动模式不对称）对姿势控制的影响。这些不对称性是通过将两个跷跷板与两个不同半径的脊线相连接，并要求特定的身体重量分布来实现的。结果表明，旨在控制前后摆动的姿势策略与个体在支撑条件较差的情况下最小化 CP 位移的能力有关，无论施加何种负荷。相比之下，更稳定支撑的参与程度必须被视为一种补充，用于确保适当的运动输出，即合力 CP 运动。在这个目标中，同时考虑了施加的负荷和更稳定支撑下的 CP 幅度。这些数据为双脚之间的相互作用提供了更多的见解，这些相互作用用于产生适当的合力 CP 运动，从而控制直立姿势。双跷跷板可以诱导不对称 CP 模式和/或不对称身体重量分布，使其成为神经和/或创伤性疾病患者康复设备的合理选择。
