노인들의 정적자세 유지를 위한 안정성 비교분석

We analyzed the trajectories of the center of mass(COM) of elderly people during their quiet upright standing for understanding their balance capabilities, which are closely related to their fall and injury, by using a three-dimensional motion capture system based on inertial measurement units. Healthy elderly men and women participated this study were divided into two groups, which have superior(n=8, M=5, F=3, age=69.75±5.95) and inferior(n=8, M=5, F=3, age=76.62±5.13) balance capabilities, respectively. The criterion of superiority in stability was whether a participant could keep a single limb standing with eyes open during at least ten seconds or not. Coordinate system was set based on x(mediolateral), y(anteroposterior), and z(vertical) axes. It is found that COM distance along the z axis is negatively correlated with COM distance along x and y axes, and velocity along the x and y axes for both groups. More remarkably, for superior group, the minimum value of COM distance along z axis is postively correlated with the minimum value of velocity along x axis. However, for inferior group, the minimum value of COM distance along z axis is positively correlated with COM distance along x and y axes. Our study shows that the characteristics of COM perturbations is useful in understanding the stability capabilities of elderly people. In addition, our study suggests that for improving the stability, the strategic program is needed to stimulate the COM oscillations in x, y, and z axes.