School of Allied Health, Faculty of Health Sciences, La Trobe University, Melbourne, Australia.
Gait Posture. 2013 Jul;38(3):507-10. doi: 10.1016/j.gaitpost.2013.01.021. Epub 2013 Feb 26.
Gait variability may be especially important to measure in people with Alzheimer's disease (AD) as it is related to risk of falling and may reflect the cognitive demand of walking. Its usefulness as an outcome measure in people with AD is currently limited by the lack of published evaluation of its reproducibility. Therefore measures of temporal and spatial gait variability were recorded using an instrumented mat on two occasions, one week apart in 16 community-dwelling people with mild to moderate probable AD. Data were combined in three ways for analysis: all available strides; all available strides from walks with mean velocity within 10cm/s of each other; and the first 12 strides from the second method. Measures of velocity, stride length and cadence variability were all found to have good reliability using an average of 64 strides from velocity-matched walks (ICC3,1 0.77-0.90) however only stride length variability reached acceptable reliability for a clinical test (ICC3,1 0.9). Estimates of the number of strides required to reach an ICC of 0.9 for velocity, cadence and stride width variability were between 169 and 212. Poor to moderate reliability of gait variability measures was obtained using 12 strides. Minimal detectable change values, calculated to reflect absolute agreement, appear to be feasible and may assist with evaluation of interventions to improve gait. Further research should examine the effects on reproducibility of gait variability measures, of systematic cueing aimed at producing consistent, optimal walking in larger groups with a range of dementia type and severity.
步态变异性在阿尔茨海默病（AD）患者中可能特别重要，因为它与跌倒风险有关，并且可能反映出行走的认知需求。目前，由于缺乏对其可重复性的发表评估，因此它作为 AD 患者的结果测量的实用性受到限制。因此，在 16 名轻度至中度可能患有 AD 的社区居住者中，使用仪器垫在两次不同的时间（相隔一周）记录了时间和空间步态变异性的测量值。数据分析时将数据以三种方式组合：所有可用步；彼此之间平均速度相差 10cm/s 的所有可用步；以及第二种方法的前 12 步。使用平均 64 步速度匹配步行（ICC3,1 0.77-0.90），发现速度、步长和步频变异性的测量值均具有良好的可靠性，但是只有步长变异性达到了临床测试的可接受可靠性（ICC3,1 0.9）。达到 ICC 为 0.9 的速度、步频和步宽变异性所需的步数估计值在 169 到 212 之间。使用 12 步获得了步态变异性测量值的较差到中等可靠性。为反映绝对一致性而计算的最小可检测变化值似乎是可行的，并且可能有助于评估改善步态的干预措施。进一步的研究应该检查针对产生一致，最佳行走的系统提示对步态变异性测量的可重复性的影响，在具有不同痴呆类型和严重程度的更大人群中。
