Vuillerme N, Chenu O, Pinsault N, Fleury A, Demongeot J, Payan Y
TIMC-IMAG Laboratory, University of Grenoble, Faculty of Medicine, La Tronche Cédex, France.
Neuroscience. 2008 Jul 31;155(1):291-6. doi: 10.1016/j.neuroscience.2008.05.018. Epub 2008 Jul 1.
We investigated the effects of a plantar pressure-based tongue-placed electrotactile biofeedback on postural control during quiet standing under normal and altered vestibular and neck proprioceptive conditions. To achieve this goal, 14 young healthy adults were asked to stand upright as immobile as possible with their eyes closed in two Neutral and Extended head postures and two conditions of No-biofeedback and Biofeedback. The underlying principle of the biofeedback consisted of providing supplementary information related to foot sole pressure distribution through a wireless embedded tongue-placed tactile output device. Center of foot pressure (CoP) displacements were recorded using a plantar pressure data acquisition system. Results showed that (1) the Extended head posture yielded increased CoP displacements relative to the Neutral head posture in the No-biofeedback condition, with a greater effect along the anteroposterior than mediolateral axis, whereas (2) no significant difference between the two Neutral and Extended head postures was observed in the Biofeedback condition. The present findings suggested that the availability of the plantar pressure-based tongue-placed electrotactile biofeedback allowed the subjects to suppress the destabilizing effect induced by the disruption of vestibular and neck proprioceptive inputs associated with the head extended posture. These results are discussed according to the sensory re-weighting hypothesis, whereby the CNS would dynamically and selectively adjust the relative contributions of sensory inputs (i.e. the sensory weights) to maintain upright stance depending on the sensory contexts and the neuromuscular constraints acting on the subject.
我们研究了基于足底压力的舌部放置式电触觉生物反馈在正常以及前庭和颈部本体感觉改变的安静站立姿势下对姿势控制的影响。为实现这一目标,14名年轻健康成年人被要求在两种头部姿势(中立位和伸展位)以及两种条件(无生物反馈和生物反馈)下尽可能静止地直立闭眼站立。生物反馈的基本原理是通过一个无线嵌入式舌部放置式触觉输出设备提供与足底压力分布相关的补充信息。使用足底压力数据采集系统记录足底压力中心(CoP)的位移。结果表明:(1)在无生物反馈条件下,相对于中立位头部姿势,伸展位头部姿势导致CoP位移增加,沿前后轴的影响大于内外侧轴;而(2)在生物反馈条件下,两种头部姿势(中立位和伸展位)之间未观察到显著差异。目前的研究结果表明,基于足底压力的舌部放置式电触觉生物反馈的可用性使受试者能够抑制与头部伸展姿势相关的前庭和颈部本体感觉输入中断所引起的不稳定效应。根据感觉重加权假说对这些结果进行了讨论,即中枢神经系统会根据感觉环境和作用于受试者的神经肌肉限制,动态且选择性地调整感觉输入的相对贡献(即感觉权重)以维持直立姿势。