Development of Isokinetic Exercise System Using High Performance MR Fluid Brake

Strengthening muscle force by training, e.g., an isokinetic exercise is widely used in rehabilitative activities or sports rehabilitations. However, many conventional isokinetic exercise machines cost expensive depending on its actuation device and safety system (hardware and software). In this study, we have developed highly safe isokinetic exercise systems using only brakes with functional fluids (ER fluid or MR fluid). Because of rapid response of these fluids, such a machine has good responsibility and controllability. In this paper, we describe basic concept and characteristics of Isokinetic Exercise system using MR fluid brake and its experimental results. In particular, high-speed (900deg/s at an elbow joint) control was realized with this system. Additionally, we suggest new training mode which we call iso-contractile exercise in this paper.