Background: Tests such as the Functional Independence Measure (FIM) are widely used measures of infirmity and burden of care. However, these scales are largely qualitative and especially problematic when assessing movement-based tasks. Effective, reliable analysis of human movement is technically complicated and expensive, but an infrared depth sensor is potentially a low-cost, portable devise which may provide a quantitative aspect to clinical testing. Our purpose was to assess the utility of a 20-sec stepping test (ST) and Kinect^TM infrared-depth sensor in providing objective evaluation of balance toward identifying disability in older adults.

Methods: Men and women between 64 and 90 years of age, consisting of independent (IG; n = 37) and dependent (DG; n = 38) living at community, geriatric day-care center in Japan. Total movement distance (TMD) and greatest displacement (MMD) were calculated from Kinect^TM recording of the ST.

Results: DG had lower FIM scores than IG. TMD and MMD were significantly greater in DG than IG, while step number and rate were lower in DG. Receiver-operator characteristic analysis showed TMD, TMD/step, MMDstep, and MMD corrected for time and height strongly discriminated between assignment to DG or IG with moderate sensitivity and specificity.

Conclusions: Greater TMD and MMD observed during a 20-sec ST appear to indicate disability with moderate sensitivity and specificity in older adults. Measures of movement distance (e.g. TMD, MMD) appear indicative of changes in dynamic balance due to a circuitous movement pattern generated by aberrant step replacement with repeated stepping-in-place.

背景：功能独立测量 (FIM) 等测试是广泛使用的疾病和护理负担测量方法。然而，这些量表在很大程度上是定性的，在评估基于运动的任务时尤其成问题。对人体运动进行有效、可靠的分析在技术上既复杂又昂贵，但红外深度传感器可能是一种低成本的便携式设备，可为临床测试提供定量方面的信息。我们的目的是评估 20 秒步进测试 (ST) 和 Kinect ^TM红外深度传感器在提供客观评估平衡以识别老年人残疾方面的效用。

方法： 64 至 90 岁的男性和女性，包括生活在日本社区老年日托中心的独立（IG； n = 37）和依赖（DG；n = 38）。从ST 的Kinect ^TM记录计算总移动距离 (TMD) 和最大位移 (MMD) 。

结果：DG 的 FIM 分数低于 IG。DG 中的 TMD 和 MMD 显着大于 IG，而 DG 中的步数和速率较低。接受者-操作者特征分析显示TMD、TMD/步、MMD步和MMD校正时间和高度强烈区分分配到DG或IG具有中等敏感性和特异性。

结论：在 20 秒 ST 期间观察到较大的 TMD 和 MMD 似乎表明老年人有中等敏感性和特异性的残疾。运动距离的测量（例如，TMD、MMD）似乎表明动态平衡的变化，这是由于通过重复原地踏步替换异常踏步而产生的迂回运动模式。