Miller Kyle T, Russell Molly, Jenks Terese, Surratt Kaddie, Poretti Kelly, Eigenbrot Samantha S, Akins Jonathan S, Major Matthew J
Northwestern University Prosthetics-Orthotics Center, Chicago, Illinois.
Department of Biomedical Engineering, Widener University, Chester, Pennsylvania.
J Prosthet Orthot. 2020 Aug 11;Online first. doi: 10.1097/JPO.0000000000000332.
Lower-limb prosthesis users (LLPUs) experience increased fall risk due to gait and balance impairments. Clinical outcome measures are useful for measuring balance impairment and fall risk screening but suffer from limited resolution and ceiling effects. Recent advances in wearable sensors that can measure different components of gait stability may address these limitations. This study assessed feasibility and construct validity of a wearable sensor system (APDM Mobility Lab) to measure postural control and gait stability.
Lower-limb prosthesis users (n=22) and able-bodied controls (n=24) completed an Instrumented Stand-and-Walk Test (ISAW) while wearing the wearable sensors. Known-groups analysis (prosthesis versus controls) and convergence analysis (Prosthetic Limb Users Survey of Mobility [PLUS-M] and Activity-specific Balance Confidence [ABC] Scale) were performed on 20 stability-related measures.
The system was applied without complications; however missing anticipatory postural adjustment data points for nine subjects affected the analysis. Of the 20 analyzed measures output by the sensors, only three significantly differed (p≤.05) between cohorts, and two demonstrated statistically significant correlations with the self-report measures.
The results of this study suggest the clinical feasibility but only partial construct validity of the wearable sensor system in conjunction with the ISAW test to measure LLPU stability and balance. The sample consisted of high-functioning LLPUs, so further research should evaluate a more representative sample with additional outcome measures and tasks.
下肢假肢使用者（LLPU）由于步态和平衡障碍，跌倒风险增加。临床结局指标有助于测量平衡障碍和跌倒风险筛查，但存在分辨率有限和天花板效应的问题。可穿戴传感器在测量步态稳定性不同组成部分方面的最新进展可能会解决这些局限性。本研究评估了一种可穿戴传感器系统（APDM移动实验室）用于测量姿势控制和步态稳定性的可行性和结构效度。
下肢假肢使用者（n = 22）和健全对照者（n = 24）在佩戴可穿戴传感器的同时完成了仪器化站立行走测试（ISAW）。对20项与稳定性相关的指标进行了已知组分析（假肢使用者与对照者）和收敛性分析（假肢使用者移动性调查[PLUS-M]和特定活动平衡信心[ABC]量表）。
该系统应用过程中未出现并发症；然而，9名受试者缺少预期姿势调整数据点，影响了分析。在传感器输出的20项分析指标中，只有3项在两组之间有显著差异（p≤.05），2项与自我报告指标显示出统计学上的显著相关性。
本研究结果表明，可穿戴传感器系统结合ISAW测试用于测量LLPU的稳定性和平衡具有临床可行性，但仅具有部分结构效度。样本由功能较高的LLPU组成，因此进一步的研究应评估更具代表性的样本，并增加其他结局指标和任务。
