Hiroki Sugiura^1,, Shuhei Takeda², Fumiyo Araki³, Sou Nobukawa⁴

This study aimed to examine the reliability and sex differences in elderly subjects for maintaining a stable posture on an unstable stool that leaned sharply in the backward and forward directions. Subjects consisted of 20 elderly males [mean age, 67.8 years; standard deviation (SD), 6.4 years] and 35 elderly females (mean age, 66.3 years; SD, 5.6 years). The ability to stand with both legs on the balance board for 20 sec was measured five times with a 1-min resting period between each trial. The stability index, displacement, angle change area, fluctuation index, and mean fluctuation index were selected as the measurement parameters. The female group was found to be superior in the angle change area, fluctuation index, and mean fluctuation index than the male group. However, no significant differences were found in both genders for all parameters. The intraclass correlation coefficient of two consecutive trials among the five trials was more than 0.67 in the third and fourth trials in both genders and the second and third trials in the female subjects for all parameters. In conclusion, a difference in results based on sex was found in the balance board test. These results suggest that when using the unstable stool balance board test in the elderly, the representative measurement values should be taken as the mean value of the third and fourth trials in males and the mean value of the second and third trials in females.

reliability, sex difference, unstable stool, dynamic balance