Deshmukh Priyanka M, Russell Colin M, Lucarino Lisa E, Robinovitch Stephen N
Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
Annu Int Conf IEEE Eng Med Biol Soc. 2012;2012:4521-4. doi: 10.1109/EMBC.2012.6346972.
About 30% of individuals over the age of 65, and 50% over age 80, fall at least once per year. Fall-related injuries cost the Canadian health care system $2.8 billion annually. Risk for falls in older adults is commonly assessed in the clinical environment using tools such as the Short Physical Performance Battery (SPPB), which include subjective assessments of postural sway while standing under various sensory conditions. This study uses wearable accelerometers and a force plate to quantify measures of postural stability during these tasks. Four participants were asked to maintain quiet stance in six different conditions, while their center of pressure (COP) and accelerations from six accelerometers were recorded. Standard deviations in signals were used as measures of postural sway. The sway observed in all sensors increased with the difficulty of the stance condition. Manipulation of vision and surface stiffness caused greater changes in sway in the AP than ML direction, while changes in stance configuration were more evident in the ML direction. Furthermore, the ankle sensor was the most sensitive in registering changes in sway when manipulating vision and surface stiffness (showing an increase of 236% over baseline values in AP sway with eyes closed and standing on foam), while the thigh was most sensitive to changes in stance width (showing an increase of 336% over baseline values in ML sway in the tandem stance condition). This study contributes in establishing the utility of wearable sensors for quantifying postural stability under various stance configurations in future studies with high-risk older adults.
65岁以上的人群中，约30%的人每年至少跌倒一次；80岁以上的人群中，这一比例为50%。与跌倒相关的伤害每年给加拿大医疗系统造成28亿加元的损失。在临床环境中，通常使用诸如简短体能测试电池（SPPB）等工具来评估老年人的跌倒风险，这些工具包括在各种感觉条件下站立时对姿势摆动的主观评估。本研究使用可穿戴式加速度计和测力板来量化这些任务期间的姿势稳定性测量值。四名参与者被要求在六种不同条件下保持安静站立，同时记录他们的压力中心（COP）和来自六个加速度计的加速度。信号的标准差被用作姿势摆动的测量值。在所有传感器中观察到的摆动随着站立条件的难度增加而增加。视觉和表面刚度的改变在前后方向（AP）上引起的摆动变化比左右方向（ML）更大，而姿势配置的变化在左右方向上更明显。此外，在操纵视觉和表面刚度时，脚踝传感器在记录摆动变化方面最敏感（闭眼站在泡沫上时，AP方向的摆动比基线值增加了236%），而大腿对站立宽度的变化最敏感（在串联站立条件下，ML方向的摆动比基线值增加了336%）。本研究有助于在未来针对高风险老年人的研究中确定可穿戴传感器在量化各种姿势配置下的姿势稳定性方面的效用。
