Assistive Technology for Real-Time Fall Prevention during Walking: Evaluation of the Effect of an Intelligent Foot Orthosis

Abstract

We present an intelligent foot orthosis (IFO) designed to prevent lateral falls during walking by employing a magnetorheological (MR) fluid brake. This study aims to demonstrate the feasibility of evaluating the effectiveness of the proposed orthosis in fall prevention. Seventeen healthy adults underwent four conditions: (1) without IFO, (2) with IFO and current-OFF, (3) with IFO current-ON, and (4) with IFO and control-ON. Gait was assessed by three-dimensional motion capture and with ground reaction force. Postural changes on the frontal plane were measured, and the mediolateral center of gravity and center of pressure inclination angle (ML COG-COP IA) was calculated. Additionally, tibialis anterior (TA) and peroneus longus (PL) muscle activity during walking were measured using surface electromyography. Results indicate a significant increase in ML COG-COP IA in (3). No significant differences were found in muscle activity between conditions. The study suggests that the posture's deviation from the lateral fall direction in (3) is primarily due to wearing the IFO, emphasizing human postural control over muscle activity. A negative correlation between ML COG-COP IA and TA muscle activity under (4), implies that individuals with lower TA muscle activity may benefit more from IFO fall prevention. In conclusion, the study demonstrates the feasibility of preventing lateral falls in human walking using the proposed orthosis with an MR fluid brake. The general efficacy of the orthosis in lateral fall prevention is suggested, emphasizing the need for further development.