Compensatory stepping in response to waist pulls in balance-impaired and unimpaired women.
Compensatory stepping in response to waist pulls in balance-impaired and unimpaired women.
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DOI：
10.1016/j.gaitpost.2004.09.004
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发表时间：
2005-11
期刊：
影响因子：
2.4
通讯作者：
Brian W. Schulz;J. Ashton-Miller;N. Alexander
中科院分区：
文献类型：
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作者：
Brian W. Schulz;J. Ashton-Miller;N. Alexander
有效的踏步反应通常是避免跌倒的关键。我们的目的是研究年龄和平衡障碍对前、后补偿性跨步策略的影响，以响应1-5%体重（BW）的腰部牵拉扰动。基于最大单足站立时间（UST），我们测试了15名平衡受损老年人（BI，UST<10 s，平均年龄=76岁），12名健康老年人（O，UST> 30 s，平均年龄=71岁）和13名健康年轻女性（Y，UST> 30 s，平均年龄=23岁）。将1-5%体重（BW）的随机前后牵拉应用于腰部，同时记录运动学和动力学恢复反应。结果表明，在4- 5%BW的后拉时，O和BI比Y多需要0.5步才能恢复平衡（P<0.01）。对于4- 5%BW的前拉，仅BI具有更大的开始迈步概率（P≤0.05或<0.02）和恢复平衡所需的平均迈步数（P<0.03）。Y型在对前后拉力的反应中，躯干伸展和躯干屈曲分别增加了93%和24%。在后向，而不是前向，O型比Y型使用更小的（P<0.007），但更多的侧向（P<0.03）步骤。BI在两个方向上的台阶着陆期间减弱其动量的能力较弱。我们的结论是，BI在两个方向上所需的额外步骤之所以发生，是因为它们的初始步骤未能适当地阻止它们的势头。在踏出前控制躯干倾斜度和在踏出落地后控制线性动量是成功的补偿踏的关键组成部分。
An effective stepping response is often critical in avoiding a fall. Our objective was to study the effects of age and balance impairment on anterior and posterior compensatory stepping strategies in response to waist pull perturbations of 1–5% body weight (BW). Based on maximal unipedal stance time (UST), we tested 15 balance-impaired old (BI, UST<10s, mean age=76 years), 12 healthy old (O, UST>30s, mean age=71 years), and 13 healthy young women (Y, UST>30s, mean age=23 years). Randomized anterior and posterior pulls of 1–5% body weight (BW) were applied to the waist while kinematic and kinetic recovery responses were recorded. Results show that O and BI required 0.5 more steps than Y to recover balance for posterior pulls of 4–5% BW (P<0.01). For anterior pulls of 4–5% BW, only BI had a greater probability of step initiation (P≤0.05 or <0.02) and mean number of steps required to recover balance (P<0.03). The Y used 93% greater torso extension and 24% greater torso flexion in responding to anterior and posterior pulls, respectively. In the posterior, but not anterior direction, O employed smaller (P<0.007), but more laterally-directed (P<0.03) steps than the Y. The BI were less able to attenuate their momentum during the step landing in both directions. We conclude that the additional steps required by the BI in both directions occurred because their initial step failed to properly arrest their momentum. Controlling torso inclination before step liftoff and linear momentum after step landing are critical components of successful compensatory stepping.