Measuring age-related differences in kinematic postural strategies under yaw perturbation
Measuring age-related differences in kinematic postural strategies under yaw perturbation
复制标题
测量偏航扰动下运动学姿势策略中与年龄相关的差异
DOI：
10.1109/memea.2018.8438804
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
E. Palermo
中科院分区：
文献类型：
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作者：
Ilaria Mileti;Juri Taborri;S. Rossi;Z. Prete;M. Paoloni;A. Suppa;E. Palermo
在外部干扰下评估与年龄相关的姿势策略对于更好地评估健康人的福尔斯风险具有重要意义。在绝大多数研究中，受试者受到俯仰角和滚转角的前后平移或旋转的干扰，以研究平衡控制所采用的姿势策略。然而，生理机制参与的响应连续偏航扰动，以保持稳定的平衡，在健康受试者仍然不清楚。10名年轻受试者（年龄：28±3岁）和10名老年人（年龄：61±4岁）被要求在两种视觉条件下站在RotoBiT 1D上：（a）睁开眼睛看固定点，（B）闭上眼睛。由ad-hoc控制软件驱动的平台在水平面上提供两个正弦旋转，具有固定振幅（±55°）和两个不同频率（0.2 Hz和0.3 Hz）。使用11个惯性测量单元收集头部、躯干、骨盆、手臂、前臂、大腿和小腿身体节段的运动学。在快速傅里叶变换后，将横向平面中的身体部分绝对旋转与平台绝对旋转进行比较。计算并分析了所有身体节段的增益（G）和相位滞后（φ）随年龄、视觉和频率条件的变化。老年受试者的G值在统计学上低于年轻受试者，所有身体节段都证明了显著的僵硬和有限的运动范围。关于φ，我们的结果表明，在老年受试者中，下肢、躯干和骨盆预期的平台运动可能补偿姿势扰动。在两组中，随着扰动频率的增加，G逐渐减小，φ逐渐延迟，而两种视觉条件下的结果相似。总之，在正弦偏航扰动下保持平衡，老年受试者采用了不同的电机控制策略，与年轻受试者相比，主要意味着减少身体运动和运动的预期。
The assessment of age-related postural strategies under external perturbation is of great interest for a better evaluation of the risk of falls in healthy humans. In the large majority of the studies, subjects have been perturbed with antero/posterior translations or rotations in the pitch and roll angles in order to investigate the postural strategies adopted for balance control. However, physiological mechanisms involved in the response to continuous yaw perturbation to maintain stable balance in healthy subjects are still unclear. Ten younger subjects (age: 28±3 years) and ten older adults (age: 61±4 years) were asked to stand on the RotoBiT1D under two visual conditions: (a) eyes opened looking at a fixation point, and (b) eyes closed. The platform, driven by an ad-hoc control software, provided two sinusoidal rotations on the horizontal plane with fixed amplitude (±55°) and two different frequencies (0.2 Hz and 0.3 Hz). Kinematics of head, trunk, pelvis, arms, forearms, thighs and shanks body-segments was gathered using eleven inertial measurement units. Body-segment absolute rotations in the transverse plane were compared to platform absolute rotation after fast Fourier transform. The gain (G) and phase lag (φ) of all body-segments were computed and analyzed as a function of age, visual and frequency conditions. G values were statistically lower in older subjects than in younger subjects for all body-segments attesting prominent stiffness and limited ranges of movement. Regarding φ, our results demonstrated that in older subjects, lower limbs, trunk and pelvis anticipated platform movement probably compensating for postural perturbations. In both groups, G decreased and φ delayed progressively by increasing the frequency of the perturbation while similar results were obtained comparing the two visual conditions. In conclusion, to maintain balance under sinusoidal yaw perturbation, older subjects adopted a different motor control strategy compared with younger subjects mainly implying reduced body-movements and the anticipation of the movement.