Smart Knee Brace (SKB) is designed to provide controlled perturbations to the human knee during walking. A dynamic model of human walking is then used to evaluate the human applied joint torques to hypothesize how the human neuro-muscular system modulates the joint torques as a response to the perturbations caused on the gait. Our results show that the neuro-muscular response to perturbations can be reasonably well characterized by including the following features in the model: (i) normal gait in the absence of perturbation, (ii) corrective torque at a joint in response to the error at that joint and other joints, (iii) a characteristic time shift in the response. We believe that these parameters can be used to characterize subjects who are more prone to falling under gait perturbations.