Applications of Predictive Simulations of Gait
First, the effect of the stiffness of an ankle-foot orthosis (AFO) on healthy gait was analyzed. Muscle forces decrease during stance phase in the lower leg when an AFO is applied, but it was found that there was little effect with stiffness. This is due to the timing of the moments that are generated by the AFO. During push-off, the ankle angle is almost zero, so the AFO is not able to provide much assistance during this phase. During the swing phase, the AFO had an adverse effect, because it counteracts the moment required to provide sufficient toe-clearance.
Second, it was found that persons with a transtibial amputation (TTA) can improve the symmetry in the joint loading of the left and right leg by choosing a slightly different gait. This increase in symmetry reduces the joint contact force in the knee and hip on the intact side, which could reduce the rate of occurrence of osteoarthritis in this joint. Also, the joint contact force in the knee on the prosthesis side is increased, which could reduce the reduction of bone mass density in this leg.
Next, a three dimensional model is developed to find predictive simulations of gait. The application of this model will be shown on gait of persons with a TTA by a reproduction of a three dimensional subject study. This study should show a similar effect of a small change in dynamics in the predictive simulation as in the subject study.
Anne Koelewijn: Influence of Stiffness of an Ankle-Foot Orthosis on Gait - a Predictive Simulation Study. ASB Annual Conference, Columbus, OH (abstract)
Anne Koelewijn: Is Kinetic Asymmetry in Below-Knee Amputee Gait Inevitable? - a Predictive Simulation Study. ISB Biannual Conference, Glasgow, UK (presentation)