Grand Valley State University, Grand Rapids, Michigan.
J Geriatr Phys Ther. 2019 Jul/Sep;42(3):E57-E66. doi: 10.1519/JPT.0000000000000175.
Postural control declines with aging and is an independent risk factor for falls in older adults. Objective examination of balance function is warranted to direct fall prevention strategies. Force platform (FP) systems provide quantitative measures of postural control and analysis of different aspects of balance. The purpose of this study was to examine the reliability and validity of FP measures in healthy older adults.
This study enrolled 46 healthy elderly adults, mean age 67.67 (5.1) years, who had no history of falls. They were assessed on 3 standardized tests on the NeuroCom Equitest FP system: limits of stability (LOS), motor control test (MCT), and sensory organization test (SOT). The test battery was administered twice within a 10-day period for test-retest reliability; intraclass correlation coefficients (ICCs), standard error of measurement (SEM), and minimal detectable change based on a 95% confidence interval (MDC95) were calculated. FP measures were compared with criterion clinical balance (Mini-BESTest and Functional Gait Assessment) and gait (10-m walk and 6-minute walk) measures to examine concurrent validity using Pearson correlation coefficients. Multiple linear regression analysis examined whether age and activity level were associated with FP performance. The α level was set at P < .05.
SOT composite equilibrium scores, MCT average latency, and LOS end point excursion measures all demonstrated excellent test-retest reliability (ICC = 0.90, 0.85, and 0.77, respectively), whereas moderate to good reliability was found for SOT vestibular ratio score (ICC = 0.71). There was large variability in performance in this healthy elderly cohort, resulting in relatively large MDC95 for these measures, especially for the LOS test. Fair correlations were found between LOS end point excursion and clinical balance and gait measures (r = 0.31-0.49), and between MCT average latency and gait measures only (r =-0.32). No correlations were found between SOT measures and clinical balance and gait measures. Age was only marginally significantly (P = .055) associated with LOS end point excursion but was not associated with SOT or MCT measures, and activity level was not associated with any of the FP measures.
FP measures provided reliable information on balance function in healthy older adults; however, small learning effects were evident, particularly for the SOT. The SEM and MDC95 for the LOS and SOT measures were relatively large for this healthy elderly cohort. A relationship between FP measures, which assess underlying balance mechanisms, and clinical balance and gait measures was not strongly supported in this study. Further research is needed to justify the value of adding FP measures to a test battery for balance assessment in older adults without a history of falls.
姿势控制随年龄增长而下降，是老年人跌倒的独立危险因素。有必要通过客观的平衡功能检查来指导预防跌倒的策略。力台（FP）系统提供了姿势控制的定量测量和平衡不同方面的分析。本研究的目的是检验 FP 测量在健康老年人中的可靠性和有效性。
本研究纳入了 46 名健康老年人，平均年龄 67.67（5.1）岁，无跌倒史。他们在神经康特等 FP 系统上接受了 3 项标准化测试：稳定性极限（LOS）、运动控制测试（MCT）和感觉组织测试（SOT）。测试组在 10 天内进行了两次测试，以评估测试-重测信度；计算了组内相关系数（ICC）、测量标准误差（SEM）和基于 95%置信区间的最小可检测变化（MDC95）。使用 Pearson 相关系数检验 FP 测量与标准临床平衡（Mini-BESTest 和功能性步态评估）和步态（10 米步行和 6 分钟步行）测量的同时效度。多元线性回归分析检验了年龄和活动水平是否与 FP 表现相关。α 水平设为 P <.05。
SOT 综合平衡评分、MCT 平均潜伏期和 LOS 终点偏移测量均具有良好的测试-重测信度（ICC = 0.90、0.85 和 0.77），而 SOT 前庭比评分具有中度至良好的信度（ICC = 0.71）。在这个健康的老年队列中，表现存在很大的变异性，导致这些测量的 MDC95 相对较大，尤其是 LOS 测试。LOS 终点偏移与临床平衡和步态测量之间存在中等至较大的相关性（r = 0.31-0.49），而 MCT 平均潜伏期仅与步态测量之间存在相关性（r =-0.32）。SOT 测量与临床平衡和步态测量之间没有相关性。年龄仅与 LOS 终点偏移有轻微显著相关性（P =.055），但与 SOT 或 MCT 测量无关，活动水平与任何 FP 测量均无关。
FP 测量在健康老年人中提供了可靠的平衡功能信息；然而，特别是对于 SOT，存在明显的学习效应。对于这个健康的老年队列，LOS 和 SOT 测量的 SEM 和 MDC95 相对较大。在本研究中，FP 测量与临床平衡和步态测量之间的关系没有得到强有力的支持，这些测量评估了潜在的平衡机制。需要进一步的研究来证明在没有跌倒史的老年人平衡评估测试中添加 FP 测量的价值。
