2005 Volume 20 Issue 4 Pages 253-257
The purpose of this study was to clarify the relationship between postural control ability and biomechanical properties consisting of sway of center of foot pressure (CFP) and muscle activities of the lower leg in elderly subjects. Twelve healthy elderly and 10 young subjects participated in this experiment. The maximal lateral shift was defined as being greater than 80% of total CFP lateral shift distance. We compared the standard deviation of the velocity of CFP sway and the muscle activity of lower leg between the two groups at maximal lateral shift. There were no significant differences among muscle activities in the elderly group, but the elderly group showed a significant positive correlation between the standard deviation of anterior-posterior sway and the activities of the peroneus longus (r=0.752, p<0.01). In conclusion, it was clarified that stability of posture in the maximal lateral shift position was obtained by using co-contraction of circumference muscles of the ankle, and that activities of the peroneus longus muscle are related to the magnitude of anterior-posterior sway of CFP in elderly subjects.
