Department of Neurology, Oregon Health and Science University, Portland, Oregon.
Veterans Affairs Portland Health Care System, Portland, Oregon.
J Neurotrauma. 2020 Jan 1;37(1):139-145. doi: 10.1089/neu.2019.6450. Epub 2019 Aug 26.
Balance and mobility issues are common non-resolving symptoms following mild traumatic brain injury (mTBI). Current approaches for evaluating balance and mobility following an mTBI can be subjective and suboptimal as they may not be sensitive to subtle deficits, particularly in those with chronic mTBI. Wearable inertial measurement units (IMU) allow objective quantification of continuous mobility outcomes in natural free-living environments. This study aimed to explore free-living mobility (physical activity and turning) of healthy and chronic mild traumatic brain injury (mTBI) participants using a single IMU. Free-living mobility was examined in 23 healthy control (48.56 ± 23.07 years) and 29 symptomatic mTBI (40.2 ± 12.1 years) participants (average 419 days post-injury, persistent balance complaints) over 1 week, using a single IMU placed at the waist. Free-living mobility was characterized in terms of macro (physical activity volume, pattern and variability) and micro-level (discrete measures of turning) features. Macro-level outcomes showed those with chronic mTBI had similar quantities of mobility compared with controls. Micro-level outcomes within walking bouts showed that chronic mTBI participants had impaired quality of mobility. Specifically, people with chronic mTBI made larger turns, had longer turning durations, slower average and peak velocities (all < 0.001), and greater turn variability compared with controls. Results highlighted that the quality rather than quantity of mobility differentiated chronic mTBI from controls. Our findings support the use of free-living IMU continuous monitoring to enhance understanding of specific chronic mTBI-related mobility deficits. Future work is required to develop an optimal battery of free-living measures across the mTBI spectrum to aid application within clinical practice.
平衡和移动问题是轻度创伤性脑损伤 (mTBI) 后常见的未解决症状。目前评估 mTBI 后平衡和移动的方法可能存在主观性和不充分性，因为它们可能对细微缺陷不敏感，尤其是在慢性 mTBI 患者中。可穿戴惯性测量单元 (IMU) 允许在自然自由生活环境中客观量化连续的移动结果。本研究旨在使用单个 IMU 探索健康和慢性轻度创伤性脑损伤 (mTBI) 参与者的自由生活移动性（身体活动和转弯）。在一周内，使用放置在腰部的单个 IMU 检查了 23 名健康对照者（48.56±23.07 岁）和 29 名有症状的 mTBI 参与者（40.2±12.1 岁）（平均受伤后 419 天，持续存在平衡问题）的自由生活移动性。自由生活移动性的特征在于宏观（身体活动量、模式和可变性）和微观水平（转弯的离散测量）特征。宏观水平结果表明，慢性 mTBI 患者的移动性与对照组相似。步行过程中的微观水平结果表明，慢性 mTBI 参与者的移动质量受损。具体而言，慢性 mTBI 患者的转弯幅度更大，转弯持续时间更长，平均速度和峰值速度较慢（均 <0.001），转弯变异性更大，与对照组相比。结果强调，移动性的质量而不是数量可以区分慢性 mTBI 与对照组。我们的研究结果支持使用自由生活 IMU 连续监测来增强对慢性 mTBI 相关移动缺陷的理解。需要进一步的工作来开发针对 mTBI 谱的最佳自由生活测量组合，以帮助在临床实践中的应用。
