The inverted Muscle Skeleton approach: moving beyond rigid exoskeletons

Exoskeleton technology has improved significantly over the past decades, yet devices are still not user-friendly. Recently, so-called exosuits—soft wearable suits that assist walking—have been proposed, but their torques are limited. In this paper we propose the inverted Muscle Skeleton (iMS) approach; this method allows for the design of wearable robotics that are less rigid and more lightweight than exoskeletons, but more powerful than exosuits. We have applied our approach to the design of a low-power knee orthosis that assists knee extension. Evaluation of the prototype during one-legged squats shows that the device can successfully generate knee extension torques that reduce muscle activity in the knee extensor muscles. The approach is promising and we believe that higher joint torques can be generated with more powerful actuators. Future work includes testing the device during walking and applying the method to the design of orthoses for other joints