2011 Volume 9 Issue 2 Pages 173-182
We investigated the decreasing effect of body asymmetry by wearing underwear with supporting function. Subjects were 14 healthy young women. They were requested to wear each combination of shirt and panty with (S) supporting function or without (N) it, in separate days for more than 6 hours per day, and then the stepping test for 1.5 minutes were performed with N-underwear. No significant differences were found among conditions in double stance and single stance phases. For pelvis inclination angle in the frontal plane, muscle activity and blood flow of gluteus medius, bilateral difference tended to decrease in all conditions with S-shirt or -panty. Especially, these were observed in subjects whose bilateral difference in N-underwear condition was larger than the mean + standard deviation (SD). Furthermore, these indices in S-shirt and -panty condition were smaller than the mean + SD for N-shirt and -panty condition. For trunk inclination angle in the frontal plane, muscle activities of erector spinae and trapezius, and blood flow in trapezius, bilateral difference with S-shirt or -panty tended to decrease, however, in a few subjects the considerable increase was also observed. In conclusion, the large bilateral differences in motion, muscle activity and blood flow tended to decrease by wearing S-shirt and/or -panty. Especially, the remarkable effect of the underwear with supporting function was found for the pelvis inclination angle, muscle activity and blood flow of gluteus medius.