Biomechanical analysis of dynamic behavior in human postural control

The functional behaviors of human standing postural control investigated when they were exposed to the long-term horizontal vibration in the sagittal plane. For complexity of human postural control, a useful alternative method which has been based on a black-box approach was taken, that is, where the feedback mechanism were lumped into a single element. The motor-driven support platform was designed as a source of vibration. The AC Servo-controlled motors produced continuous anterior/posterior (AP) motion. The data was analyzed, both in the time domain and in the frequency domain. The cross-correlation and the coherency function were estimated. Subjects behaved as a non-rigid pendulum with a mass and a spring throughout the whole period of the platform motion. It is consistent with the scheme that we adopted in this study.