Fig. 5.

In an example showing inertia-related error, a subject (body mass = 50.0 kg) slipped forward and experienced a backward balance loss during the stance phase in gait after her right (slipping) limb landed on the movable component of a device. The time-history results from the right limb shown here include (a) the center of pressure (COP, solid line) and COP offset (dash line) as well as a comparison between the uncorrected (dash) and the corrected (solid) (b) horizontal component of the ground reaction force (GRF), (c, e, and g) resultant joint moments, and (d, f, and h) resultant joint forces at ankle; knee and hip, respectively. Time is normalized as a percentage of the total duration of the stance phase (0.81-s) from its touchdown, t_0, to liftoff, t_f, from the movable component. Two thin vertical lines mark the timing of the liftoff (solid) and touchdown (dash) during the recovery with the contralateral limb, which landed outside of the moving component without affecting the results of the right limb shown here. The COP is relative to its value at t₀. The GRF and the resultant joint forces are normalized by body weight, and the resultant joint moments by the body mass, where positive represents extension (plantar flexion) moments.