Interlimb Parallel-Link Powered Orthosis (IPPO) for Gait Assistance with Lateral Weight Bearing

Abstract

Many institutions have been developing wearable robots for people with motor impairment. However, most of these robots still require arm support by means of crutches or a walker. Arm support is necessary to ensure stability of lateral balance by weight bearing toward the user's stance leg during the swing phase. In this study, we developed a wearable robot prototype with a mechanism for assisting lateral weight bearing. Our wearable robot is conventional in the sense that it possesses actuators in the hip, knee, and ankle joints. In addition, the robot has the degree of freedom for lateral movements of the pelvis that assist lateral weight bearing. An experimental setup of the prototype with a normal (unimpaired) subject confirmed that the mechanisms of the wearable robot were able to safely assist walking. Furthermore, we confirmed that the lateral movement amplitude of the subject's trunk increased when the assistance of the lateral weight bearing was enabled.