Fig. 4

Ground reaction forces during stair ascent and descent under various levels of unloading. Average vertical, anteroposterior and mediolateral GRFs over all subjects for a single gait cycle during stair ascent and descent. Different line colors correspond to investigated BWS levels and shaded area to one standard deviation from mean baseline GRFs. Black arrows specify average vertical GRF peak (Fz2, Fz4) and plateau (Fz3) locations for the baseline condition and black dotted line visualizes the zero-force level