Bioengineering Graduate Program, School of Engineering, University of Kansas, United States.
Department of Mechanical Engineering, School of Engineering, University of Kansas, United States.
Gait Posture. 2022 Jan;91:276-283. doi: 10.1016/j.gaitpost.2021.10.017. Epub 2021 Oct 29.
Falls in older adults are often multifactorial, but can be linked to diminished sensation capabilities from age-related neural degeneration. Rambling-trembling (RM-TR) decomposition may provide insight into the relation between sensorineural function and postural sway, with both research and clinical applications.
What are the effects of perturbed somatosensation on RM-TR-derived measures of center of pressure (COP) during quiet standing?
Fifty-two healthy young adults (22.10 ± 1.88 years) participated in the study. Participants stood on two force plates with a standardized stance width and foot angle, with eyes open (EO) or eyes closed (EC). Foam with different thicknesses ranging from 1/8″ to 1″ (F1-F4) was placed under the feet to interfere with intact sensory input and simulate varying degrees of somatosensory deficit. Force and moment data were used to calculate COP, RM, and TR time series. Mean velocity, acceleration, and jerk in the anteroposterior (AP) and mediolateral direction (ML) were extracted for comparison.
The EO condition remained relatively constant regardless of foam thickness. The EC condition showed increasing changes from baseline to each of the foam conditions. COP captures the smallest change in foam thickness, but RM provides a robustness across parameters that is not found in COP or TR. RM jerk in the AP direction showed significantly greater changes from baseline to F4 than the COP or TR counterparts. In the ML direction, TR jerk showed a sharper contrast between foam conditions than COP and RM.
Findings suggest that RM-TR-derived measures may act as a compliment to, or provide a greater degree of sensitivity than, traditional COP measures and aid in the initial detection and monitoring of fall risk in aging and pathological populations.
老年人跌倒通常是多因素的，但可能与年龄相关的神经退行性变导致感觉能力下降有关。摇摆颤动（RM-TR）分解可能提供有关感觉神经功能与姿势摆动之间关系的深入了解，具有研究和临床应用价值。
感觉受到干扰对安静站立时 RM-TR 衍生的中心压力（COP）指标有什么影响？
52 名健康的年轻成年人（22.10±1.88 岁）参加了这项研究。参与者以标准的站立宽度和脚角度站在两个力板上，睁眼（EO）或闭眼（EC）。将从 1/8″到 1″（F1-F4）不同厚度的泡沫放在脚下，以干扰完整的感觉输入并模拟不同程度的感觉缺失。使用力和力矩数据来计算 COP、RM 和 TR 时间序列。提取前-后（AP）和中-侧（ML）方向的平均速度、加速度和急动度进行比较。
EO 条件无论泡沫厚度如何都保持相对稳定。EC 条件从基线到每个泡沫条件都显示出增加的变化。COP 捕捉到泡沫厚度的最小变化，但 RM 提供了一种在 COP 或 TR 中找不到的跨参数稳健性。AP 方向的 RM 急动度从基线到 F4 的变化明显大于 COP 或 TR 对应值。在 ML 方向，TR 急动度与 COP 和 RM 相比，泡沫条件之间的对比度更明显。
研究结果表明，RM-TR 衍生的指标可能是对传统 COP 指标的补充，或者提供更高的敏感性，有助于在衰老和病理人群中更早期检测和监测跌倒风险。
