Estimation of postural control strategy during continuous perturbation

Stability is an important aspect for every moving object and millions of people spend a good deal of their time on their feet for standing, walking, or running. Compared to static balance, dynamic balance with presence of external perturbation requires more complex strategy. The purpose of this study was to investigate the multi-segment of human postural control strategy organization in continuous perturbation balance task between ankle-hip angle as collective variable. We examined the transition of Center of Mass (COM)-Center of Pressure (COP) and ankle-hip angle pattern in moving platform balance paradigm. Eight healthy young adults stood on a moving platform in the anterior-posterior direction continuously within the frequency range 0.2–0.8 Hz and vice versa with eyes opened. COM, COP, and ankle-hip angle changed from in-phase to anti-phase at a certain point frequency of support surfaces. From the cross-correlation coefficient calculation, higher frequency shows negative correlation between the ankle-hip angle which mean these two variables were moving in the different phase direction. These results indicate that joint angle sway also could be one of the collective variables in order to determine postural strategy determination.