Figure 3

Two-arm UE loading to stabilize against perturbation pulse (15% body-weight, 250 msec) applied near model COM in either forward or side (i.e., right) direction under either optimal (CONST: OPT) or maximal constant (CONST: MAX) muscle excitation or controller modulation of muscle excitation under joint (JT), COM-acceleration (ACC) or combined (JT + ACC) feedback.