Optimal Control and Biomechanics of Ambulation with Spring-Loaded Crunches

摘要

Standard underarm or forearm crutches have some drawbacks induced by their rigid legs. Sping-loaded crutches can reduce the impact effect. However, whether or not they also improve propulsion is an open problem. We formulate a problem of the optimal performance of spring-loaded crutches and propose a numerical approach to solve the problem. Then, the numerical optimal values are incorporated to the innovative design of a pair of spring-loaded crutches. To evaluate the crutches' performance, we have conducted standard biomechanical experiments for a number of male subjects under two conditions: walking with standard crutches and with spring-loaded crutches. Three dimensional kinematic data and ground reaction force were recorded and analysed. It was observed that optimized spring-loaded crutches can efficiently propel the crutch walkers, which conforms to the theory.