2011 Volume 9 Issue 2 Pages 101-106
The present study investigated the trunk and pelvis inclination movement angles in the frontal plane in single stance phase during stepping in place. Subjects were 26 healthy young adults. All measurements were taken with subjects standing barefoot on a force platform. Subjects performed the stepping for 120 s at 1 Hz frequency. The sum of the durations of double and single stance phases was approximately 1000 ms for each leg. Maximal inclination angle of the supporting leg in the frontal plane, and maximal hip and knee flexion angles did not differ significantly between the right and left single stance phase. These results clarified that right and left leg movements in the stepping were carried out symmetrically at 1 Hz frequency. The pelvis significantly inclined toward the supporting leg in the single stance phase. The trunk significantly inclined toward the supporting leg in the right stance phase, but not in the left. This indicated that the trunk inclination angle in the left stance phase was similar to that during quiet standing. The results suggested that the postural reference frame based on gravitational direction more strongly influenced balance during stepping in the left stance phase than in the right. No significant correlation was found between the trunk and leg inclination movement angles in both single stance phases, or between the right and left single stance phase in the trunk inclination movement angles. Individual variation in balance strategy between the trunk and leg in the frontal plane appears to occur during the stepping.
