805 Mechanical property of ankle-foot orthosis based on property of hemiplegic ankle and on gait characteristics

Abstract

An ankle-foot orthosis (AFO) is a device widely used by hemiplegic patients to assist their gait. The aim of this study is to estimate an adequate mechanical property of an AFO based on a passive property of ankle. First, we examine mechanical properties of hemiplegic ankle and their AFO prescribed suitably, and then evaluate the correlation between these two properties. The results show that AFO plantar stiffness has significant correlations (p<0.05) with ankle resistive moment at a knee-extended posture and with ankle dorsal stiffness at a knee-flexed posture. The former correlation gives reasonable estimation at initial stance phase, and the latter at swing phase. Next, we examine a relationship between the AFO stiffness and gait characteristics of hemiplegic subjects. The results show that the regression derived from the correlations are useful for estimation of adequate AFO plantar stiffness.