The instrument is a part of the Selection MED line that guides the knee flexion muscles. The device is popularly known as the Leg Curl MED. The device especially works on the muscles and joints of knee to aid it to bend. It does this by a guided and controlled bending movement. The instrument has two rollers or cushions. The lower one helps to rest the calf by moving downward at the time of motion. This makes the leg bend. The upper one holds leg in place to keep it on the correct position. The machine is approved by the EEC 93/42 and the TÜV like other Selection MED line range. This certifies its safety and utilization. The device is applicable to any age or the physical condition, specifically if the patient is in the first stage of rehabilitation after an injury or surgery. As for instance, after knee prosthesis, the device helps likewise to the patients.