ERIK: a controllable exercise equipment for the lower limb

We reports an isokinetic exercise equipment prototype, named the ERIK, for the lower limb. The ERIK allows a type of single-limb squat exercise providing a translational load to the swing leg while loading on the stance leg in the standing position. This training produces loads to the gluteal muscles that are effective for the prevention of the knee valgus moment, a major factor in anterior cruciate ligament injuries. To enhance the quality of the load, an electro-rheological (ER) fluid brake system is implemented. The ER brake can reversibly control its resistive torque with a rapid response. Nevertheless the high resistance created within the trainee's wide motion area to provide some training manners by controlling the brake torque, the ERIK has the advantage of safety since it has only a passive element for the load. The control methods for the training and certification of their performance through basic experiments are addressed in the paper.