Effect of a Hybrid Ankle Foot Orthosis Made of Polypropylene and Fabric in Chronic Hemiparetic Stroke Patients

Abstract

The ankle foot orthosis (AFO) has been used for control of ankle motion in stroke patients for a long time. However, studies on the materials used in construction of AFOs have been limited. In this study, the authors attempted to investigate the effect of a hybrid AFO made with polypropylene and fabric in comparison with a conventional plastic AFO in terms of convenience and effect in patients with chronic hemiparetic stroke. Seventeen patients with chronic hemiparetic stroke who have used plastic AFOs were recruited for this study. Two types of AFOs were used: plastic AFO made with polypropylene and hybrid AFO made with polypropylene covered with canvas fabric, which were individually molded and fitted. Convenience was evaluated using a self-developed questionnaire on patients' satisfaction and weights of AFO, and effect was evaluated using gait analysis. On the satisfaction questionnaire, satisfaction was greater for the hybrid AFO, and it was lighter in weight than the plastic AFO (P < 0.05). In gait analysis, faster walking speed, larger mean and peak ankle dorsiflexion angles, and ankle dorsiflexion angles at heel strike and toe off were observed for the hybrid and plastic AFOs compared with barefoot (P < 0.05). No significant difference was observed between the two orthoses, except for ankle dorsiflexion angle at heel strike, in which the plastic AFO showed higher ankle dorsiflexion angle than did the hybrid AFO. According to the results of this study, the hybrid AFO showed a similar effect in function, except for ankle dorsiflexion angle at heel strike, and was superior with regard to convenience compared with the conventional plastic AFO in chronic hemiparetic stroke patients. Therefore, it seems that, in general, the hybrid AFO can be recommended for hemiparetic stroke patients who require an AFO.