Response time is more important than walking speed for the ability of older adults to avoid a fall after a trip
Response time is more important than walking speed for the ability of older adults to avoid a fall after a trip
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DOI：
10.1016/s0021-9290(01)00198-1
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发表时间：
2002-02-01
影响因子：
2.4
通讯作者：
Grabiner, MD
中科院分区：
文献类型：
--
作者：
van den Bogert, AJ;Pavol, MJ;Grabiner, MD
我们以前报道过，老年人从向前的旅行中恢复并使用“降低”策略的概率随着步行速度的降低和更快的反应时间而增加，为了确定这些变量的受试者内相互作用，我们提出了三个问题：（1）恢复脚降低到地面时的身体方向（“倾斜角”）对成功恢复至关重要吗？(2)一个简单的倒立摆模型，使用受试者特定的步行速度和响应时间作为输入变量，可以预测这个身体的方向，从而成功的恢复？(3)较慢的步行速度或更快的反应时间更有效地防止跌倒后旅行？倾斜角度是成功的恢复步骤的完美预测器，表明恢复脚放置必须在倾斜角度超过与垂直方向成23度至26度的临界值之前发生。倒立摆模型从行走速度和响应时间预测倾斜角度，误差为0.4+/-2.2度，相关系数为0.93。该模型预测，更快的反应时间比较慢的步行速度更重要的成功恢复。在一个有跌倒风险的典型个体中，我们预测反应时间减少到正常值可以使安全步行速度增加77%。该数学模型产生了针对患者的跌倒预防建议，并提出了指导治疗干预以改善老年人反应时间的重要性。(C)2002爱思唯尔科技有限公司版权所有。
We previously reported that the probability of an older adult recovering from a forward trip and using a "lowering" strategy increases with decreased walking velocity and faster response time, To determine the within-subject interaction of these variables we asked three questions: (1) Is the body orientation at the time that the recovery foot is lowered to the ground ("tilt angle") critical for successful recovery? (2) Can a simple inverted pendulum model, using subject-specific walking velocity and response time as input variables, predict this body orientation, and thus success of recovery? (3) Is slower walking velocity or faster response time more effective in preventing a fall after a trip? Tilt angle was a perfect predictor of a successful recovery step, indicating that the recovery foot placement must occur before the tilt angle exceeds a critical value of between 23degrees and 26degrees from vertical. The inverted pendulum model predicted the tilt angle from walking velocity and response time with an error of 0.4+/-2.2degrees and a correlation coefficient of 0.93. The model predicted that faster response time was more important than slower walking velocity for successful recovery. In a typical individual who is at risk for falling, we predicted that a reduction of response time to a normal value allows a 77% increase in safe walking velocity. The mathematical model produced patient-specific recommendations for fall prevention, and suggested the importance of directing therapeutic interventions toward improving the response time of older adults. (C) 2002 Elsevier Science Ltd. All rights reserved.