Akinlosotu Ruth Y, Alissa Nesreen, Sorkin John D, Wittenberg George F, Westlake Kelly P
Department of Physical Therapy and Rehabilitation Science, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
Baltimore VA Medical Center Geriatrics Research, Education, and Clinical Center, Baltimore, MD 21201, USA.
Brain Sci. 2020 Aug 20;10(9):574. doi: 10.3390/brainsci10090574.
The objective of this study was to examine age-related differences in arm and trunk responses during first and repeated step induced balance perturbations. Young and older adults received 10 trials of unpredictable lateral platform translations. Outcomes included maximum arm and trunk displacement within 1 s of perturbation and at first foot lift off (FFLO), arm and neck muscle activity as recorded using electromyography (EMG), initial step type, balance confidence, and percentage of harness-assisted trials. Compared to young adults, older adults demonstrated greater arm and trunk angular displacements during the first trial, which were present at FFLO and negatively associated with balance confidence. Unlike young adults, recovery steps in older adults were directed towards the fall with a narrowed base of support. Over repeated trials, rapid habituation of first-trial responses of bilateral arm and trunk displacement and EMG amplitude was demonstrated in young adults, but was absent or limited in older adults. Older adults also relied more on harness assistance during balance recovery. Exaggerated arm and trunk responses to sudden lateral balance perturbations in older adults appear to influence step type and balance recovery. Associations of these persistently amplified movements with an increased reliance on harness assistance suggest that training to reduce these deficits could have positive effects in older adults with and without neurological disorders.
本研究的目的是检验在首次及重复的步诱发平衡扰动过程中，手臂和躯干反应的年龄相关差异。年轻和年长成年人接受了10次不可预测的侧向平台平移试验。结果包括扰动后1秒内及首次抬脚离地（FFLO）时的最大手臂和躯干位移、使用肌电图（EMG）记录的手臂和颈部肌肉活动、初始步类型、平衡信心以及安全带辅助试验的百分比。与年轻成年人相比，年长成年人在首次试验期间表现出更大的手臂和躯干角位移，这些位移在FFLO时出现，且与平衡信心呈负相关。与年轻成年人不同，年长成年人的恢复步朝向跌倒方向，支撑面变窄。在重复试验中，年轻成年人双侧手臂和躯干位移以及EMG振幅的首次试验反应迅速习惯化，但年长成年人中不存在或有限。年长成年人在平衡恢复过程中也更多地依赖安全带辅助。年长成年人对突然的侧向平衡扰动的过度手臂和躯干反应似乎会影响步类型和平衡恢复。这些持续放大的运动与对安全带辅助的依赖增加之间的关联表明，针对减少这些缺陷的训练可能对患有和未患有神经疾病的年长成年人产生积极影响。
