BACKGROUND In the last few decades, research related to balance in older adults has been conducted in lab-based settings. The lack of portability and high cost that is associated with the current gold standard methods to quantify body balance limits their application to community settings such as independent living facilities. The purpose of the study was to examine the relative and absolute reliability and the convergent validity of static standing balance performance using an accelerometer device. METHODS A total of 131 participants (85% female, mean age 80 ± 8 years) were included for the validity aim, and a subsample of 38 participants were enrolled in the reliability testing (89% female, mean age 76 ± 7 years). The root-mean-square (RMS) and normalized path length (NPL) for sway in antero-posterior (AP) and medio-lateral (ML) directions were calculated for different standing balance conditions. Test-retest reliability was assessed over two testing visits occurring 1 week apart using the intraclass correlation coefficient (ICC) for relative reliability, and the minimal detectable change (MDC) was calculated for the absolute reliability. Spearman's rank correlation coefficient was used to test convergent validity at baseline between balance measurements and related mobility measures. RESULTS Reliability of balance performance using accelerometers was good to excellent with ICC values ranging from 0.41 to 0.83 for RMS sway and from 0.49 to 0.82 for NPL sway. However, the ICC during semi-tandem stance in A-P direction was 0.35, indicating poor reliability. The MDC of the sway measurements ranged from 2.4 to 9.4 for the RMS and 5.2 to 13.8 for the NPL. Balance measurements were correlated with mobility measurements. CONCLUSIONS Using a portable accelerometer to quantify static standing postural control provides reliable measurements in community settings.

中文翻译：

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在独立生活的老年人中，在社区环境中记录的仪器化姿势摇摆测量的心理测量特性。

背景技术在过去的几十年中，已经在基于实验室的环境中进行了与老年人的平衡有关的研究。当前的量化身体平衡的黄金标准方法缺乏便携性和高成本，这限制了它们在社区环境（例如独立生活设施）中的应用。该研究的目的是使用加速度计设备检查静态站立平衡性能的相对和绝对可靠性以及收敛有效性。方法：共计131名参与者（女性占85％，平均年龄80±8岁），并进行了38位参与者的子样本参与可靠性测试（女性占89％，平均年龄76±7岁）。对于不同的站立平衡条件，计算了前后（AP）和中外侧（ML）方向上摇摆的均方根（RMS）和归一化路径长度（NPL）。使用组内相关系数（ICC）对相隔1周的两次测试访问进行重测信度评估，以得到相对信度，并计算最小可检测变化（MDC）的绝对信度。Spearman等级相关系数用于检验平衡测量和相关流动性测量之间基线的收敛有效性。结果使用加速度计的平衡性能的可靠性好到极好，RMS摆幅的ICC值范围从0.41到0.83，NPL摆幅的ICC值范围从0.49到0.82。但是，沿AP方向半串联的ICC为0.35，表示可靠性差。摆幅测量值的MDC范围从RMS的2.4到9.4，对于NPL的范围从5.2到13.8。平衡测量与流动性测量相关。结论使用便携式加速度计来量化静态站立姿势控制可在社区环境中提供可靠的测量结果。