Figure 3.

Simple feedback model of postural control used to predict muscle activity during balance responses. (a) The mechanics of the CoM during the balance task is approximated as an inverted pendulum on a moving cart. Experimentally measured accelerations of the platform were applied to the cart so that realistic acceleration, velocity, and displacement trajectories of the platform were modeled. (b) The perturbation acceleration generates a disturbance torque at the base of the pendulum. Kinematics of the horizontal CoM were controlled with a delayed-feedback law that generated model muscle activation patterns, which were compared to those measured experimentally. The model muscle activation was passed through a first-order muscle model to generate a stabilizing torque about the representative joint.