Study of standing balance assessment by probe reaction time measurement ; a view of attention demands

本研究的总体目标是利用探针反应时间测量在站立负荷平衡条件下的站立平衡功能评估。以10 ~ 80岁健康受试者和中枢神经疾病患者为研究对象，分别在静力板上站立(1)、静力板上抬臂90度站立(2)和静力板上覆盖不稳定聚氨酯泡沫站立(3)三种站立状态下，测量对声音提示和压力中心（COPE）的咬肌肌电反应时间。10岁~ 50岁健康受试者的反应时间有规律，COPE从(1)状态到(3)状态依次增加。另一方面，60多年来，与年轻受试者相比，反应时间延迟，COPE从(1)条件到(3)条件依次增加。特别是80年的反应时间按(1)、(2)、(3)的顺序显著延迟。脑卒中患者的反应时间比健康人延迟。脑干、丘脑、小脑损伤组与其他部位损伤组相比，前者的反应时间明显延迟。前者的反应时间按(1)、(2)、(3)的顺序延迟。这些结果表明，老年人和损伤区患者的注意需求分布对站立平衡功能的影响取决于站立平衡条件的负荷。结果进一步表明，探针反应时间测量可以用于评价站立平衡功能。

The overall objective of this study was to develop a standing balance function assessment utilized the probe reaction time measurement under the loaded balance condition in standing. The masseter EMG reaction times responding to the sound cue and the center of pressure excursion (COPE) were measured under the three standing conditions which consisted of the static standing on force plate (1), the static standing elevated arm at 90 degrees with 1Kg weight on force plate (2), and the static standing on force plate covered unstable urethane foam (3), in the healthy subjects from 10 years to 80 years and the patients with central nervous diseases. The reaction times were regular and the COPE were increased in sequence from (1) -condition to (3), in the healthy subjects from 10 years to 50 years. On the other hand, the reaction times were delayed compared young subjects and the COPE were increased in sequence from (1) -condition to (3) in over 60 years. Especially, the reaction times in 80 years were delayed significantly in order of (1), (2), and (3). In the stroke patients, the reaction times were delayed compared with the healthy subjects. In comparing between the patients injured on brain stem, thalamus and cerebellum, and the patients injured on other regions, the formers were delayed significantly in the reaction time. Furthermore, the former's reaction time was delayed in order of (1), (2), an (3). These results suggested that the attentional demand distributions of the older adults and the patients with the injured regions influenced the standing balance function, was depended on the load of standing balance condition. Results further suggested that the probe reaction time measurement was utilized possibly to evaluate the standing balance function.