...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>IEEE transactions on neural systems and rehabilitation engineering >Online mutability of step direction during rapid stepping reactions evoked by postural perturbation
【24h】

Online mutability of step direction during rapid stepping reactions evoked by postural perturbation

机译：姿势扰动引起的快速迈步反应过程中迈步方向的在线可变性

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Stepping reactions are often triggered rapidly in response to loss of balance. It has been unclear whether spatial step parameters are defined at time of step-initiation or whether they can be modulated online, during step execution, in response to sensory feedback about the evolving state of instability. This study explored the capacity to actively alter step direction subsequent to step initiation in six healthy young-adult subjects. To elicit forward-step reactions, subjects were released suddenly from a tethered forward lean. A second perturbation (medio-lateral support-surface translation) was applied at lags of 0-200 ms. Active reaction to the second perturbation was determined primarily through analysis of swing-leg hip-abductor activation. In addition, to gauge the biomechanical consequence of the changes in muscle activation, we compared the measured medio-lateral swing-foot displacement to that predicted by a simple passive mechanical model. Perturbations at 0-100 ms lag evoked active medio-lateral swing-foot deviation, allowing balance to be recovered with a single step. However, when the second perturbation occurred near foot-off (200-ms lag), there was no evidence of active alteration of step direction and subjects typically required additional steps to recover balance. The results suggest that step direction can be reparameterized during early stages of stepping reactions, but that step direction was not actively modulated in response to perturbation arising near start of swing phase.
机译：通常会因失去平衡而迅速触发步进反应。尚不清楚是否在步骤启动时定义了空间步骤参数，或者是否可以在步骤执行过程中响应于关于不稳定性演变状态的感官反馈，对它们进行在线调制。这项研究探讨了在六名健康的年轻成人受试者中，在逐步启动后主动改变步伐方向的能力。为了引起前瞻性反应，受试者被束缚的前倾瘦身突然释放。在0到200毫秒的延迟处应用第二次扰动（中外侧支撑表面平移）。对第二次扰动的主动反应主要通过分析摆腿髋外展肌的激活来确定。此外，为了评估肌肉激活变化的生物力学后果，我们将测量的中外侧摆脚位移与通过简单的被动机械模型预测的位移进行了比较。滞后0-100毫秒的摄动引起了活跃的中外侧摆动脚的偏离，使平衡可以通过一个步骤来恢复。但是，当第二次扰动发生在脚步附近（滞后200毫秒）时，没有证据表明脚步方向发生主动改变，受试者通常需要采取其他步骤来恢复平衡。结果表明，在步进反应的早期阶段，可以重新设置步进方向的参数，但是，由于在摆动阶段开始时出现的扰动，步进方向并未得到主动调节。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号