Kimijanová Jana, Bzdúšková Diana, Hirjaková Zuzana, Hlavačka František
Department of Behavioral Neuroscience, Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia.
Front Hum Neurosci. 2021 Oct 21;15:771446. doi: 10.3389/fnhum.2021.771446. eCollection 2021.
Gait initiation (GI) challenges the balance control system, especially in the elderly. To date, however, there is no consensus about the age effect on the anticipatory postural adjustments (APAs). There is also a lack of research on APAs in older adults after proprioceptive perturbation in the sagittal plane. This study aimed to compare the ability of young and older participants to generate APAs in response to the vibratory-induced perturbation delivered immediately before GI. Twenty-two young and 22 older adults performed a series of GI trials: (1) without previous vibration; (2) preceded by the vibration of triceps surae muscles; and (3) preceded by the vibration of tibialis anterior muscles. The APAs magnitude, velocity, time-to-peak, and duration were extracted from the center of pressure displacement in the sagittal plane. Young participants significantly modified their APAs during GI, whereas older adults did not markedly change their APAs when the body vertical was shifted neither backward nor forward. Significant age-related declines in APAs were observed also regardless of the altered proprioception.The results show that young adults actively responded to the altered proprioception from lower leg muscles and sensitively scaled APAs according to the actual position of the body verticality. Contrary, older adults were unable to adjust their postural responses indicating that the challenging transition from standing to walking probably requires higher reliance on the visual input. The understanding of age-related differences in APAs may help to design training programs for the elderly specifically targeted to improve balance control in different sensory conditions, particularly during gait initiation.
步态起始（GI）对平衡控制系统构成挑战，在老年人中尤为如此。然而，迄今为止，关于年龄对预期姿势调整（APA）的影响尚无共识。对于老年人在矢状面本体感觉受扰后的APA也缺乏研究。本研究旨在比较年轻和年长参与者在GI前立即施加的振动诱发扰动后产生APA的能力。22名年轻人和22名老年人进行了一系列GI试验：（1）之前无振动；（2）在腓肠肌振动之后；（3）在胫骨前肌振动之后。从矢状面压力中心位移中提取APA的幅度、速度、峰值时间和持续时间。年轻参与者在GI期间显著改变了他们的APA，而当身体垂直方向既不向后也不向前移动时，老年人并没有明显改变他们的APA。无论本体感觉如何改变，均观察到与年龄相关的APA显著下降。结果表明，年轻人积极应对来自小腿肌肉的本体感觉变化，并根据身体垂直度的实际位置敏感地调整APA。相反，老年人无法调整他们的姿势反应，这表明从站立到行走的挑战性过渡可能需要更高程度地依赖视觉输入。了解APA中与年龄相关的差异可能有助于为老年人设计专门针对改善不同感觉条件下平衡控制的训练计划，尤其是在步态起始期间。
