압력중심 좌표를 이용한 휠체어 사용자의 앉기 자세조절능력 평가 : 예비 연구

Seated balance is the essential ability to maintain a posture without sway on a solid support surface, especially for wheelchair users for activities of daily living(ADL), transferring, and avoiding fall. The center of pressure(COP) has been using as a useful indicator for quantitative balance evaluation. The purpose of this study was to assess the seated balance using COP trajectory analysis methods. Sixteen healthy adult people and sixteen wheelchair users participated in this study. Every subject was asked to maintain four different sitting positions(upright, forward, backward, and side leaning) for 20 seconds. The COP was recorded using a pressure mat while subjects were performing those four-position sitting tests. Mean velocity in anteroposterior(AP) and mediolateral(ML) directions, the phase plane parameter, the root mean square distance in AP and ML directions were analyzed and compared between the two groups. Variables in upright, forward, and backward leaning positions showed similar results in mean comparisons. However, most variables in side leaning, the patient group showed significantly larger than those of the healthy group. Based on these results, the wheelchair user group has worse seated balance ability than the healthy group in the seated balance tests. Also, If we normalize the degree of leaning, the COP will be useful for the seated balance assessment.