Tanaka T, Noriyasu S, Ino S, Ifukube T, Nakata M
Department of Physical Therapy, School of Health Sciences, Sapporo Medical University, Japan.
IEEE Trans Rehabil Eng. 1996 Jun;4(2):84-90. doi: 10.1109/86.506405.
The purpose of this study was to examine the relationship between toe pressure and tactile sensitivity in the great toe and to describe two newly developed measurements of postural stability. The subjects of the study were 21 healthy volunteers. The subjects were divided into two age groups, the young group (mean 21.0 +/- 1.6 years, 7 males and 6 females), and the elderly group (mean 71.4 +/- 2.8 years, 4 males and 4 females). The methods and materials used for the first experiment (balance test): The instrument for measuring standing balance was a force plate. Data were analyzed to provide two main variables: 1) body sway index (SI: mm) and 2) toe pressure (%BW/cm2). The subjects were asked to stand in a relaxed posture for 20 s. The variables of body sway were measured in four conditions: normal surface with eyes open or closed, and soft surface with eyes open or closed. Second experiment (tactile sense test): This experiment utilized a new system which was developed for measuring the tactile sensation. The tactile threshold value was measured with the subject seated in a chair, the back supported, and the hips and knees flexed at 90 degrees. The contactor pulled and pushed the toe longitudinally along its axis at a constant velocity of 1 mm/s. There were significant differences between the young and elderly groups in the tactile sense of the great toe (p < .001). No significant difference between age groups was found for postural sway while the subjects stood on the normal surface with eyes open; however, when they stood on the soft surface with their eyes open and closed, the elderly showed significantly more sway (p < 0.01) than the young. Moreover, the maximal great toe pressure in the elderly group was significantly greater than that in the young group. The results suggest that the reduced tactile sense, deprivation of visual information, and toe pressure weakness are all important factors associated with postural instability.
本研究的目的是检验大脚趾的趾压与触觉敏感度之间的关系，并描述两种新开发的姿势稳定性测量方法。该研究的受试者为21名健康志愿者。受试者被分为两个年龄组，年轻组（平均年龄21.0±1.6岁，7名男性和6名女性）和老年组（平均年龄71.4±2.8岁，4名男性和4名女性）。第一次实验（平衡测试）所使用的方法和材料：测量站立平衡的仪器是测力板。对数据进行分析以提供两个主要变量：1）身体摆动指数（SI：毫米）和2）趾压（%体重/平方厘米）。要求受试者以放松姿势站立20秒。在四种条件下测量身体摆动变量：睁眼或闭眼在正常表面，以及睁眼或闭眼在柔软表面。第二次实验（触觉测试）：本实验采用了一种新开发的用于测量触觉的系统。触觉阈值是在受试者坐在椅子上、背部得到支撑且臀部和膝盖弯曲成90度的情况下进行测量的。接触器以1毫米/秒的恒定速度沿脚趾轴线纵向推拉脚趾。大脚趾的触觉在年轻组和老年组之间存在显著差异（p<0.001）。当受试者睁眼站在正常表面时，各年龄组在姿势摆动方面未发现显著差异；然而，当他们睁眼和闭眼站在柔软表面时，老年人的摆动明显比年轻人更多（p<0.01）。此外，老年组的最大大脚趾压力显著高于年轻组。结果表明，触觉减退、视觉信息缺失和趾压减弱都是与姿势不稳定相关的重要因素。
