From 1999 to 2008, an estimated amount of 6.6 million people had suffered knee injuries alone in the United States. In a survey done recently, about 26 percent of adults have the leg or knee-related pain and that increased when participant got older or was involved in some type of athletic activity. My objective was to create knee exoskeleton that provided powerful yet comfortable and light enough to be worn by a human. Electric motor, far the most common actuator used in robots and prosthetic devices cannot be used due to constraints of being light and powerful at the same time. Motors that are lightweight have weak torque and vice-versa for the opposite. However, studies on the human muscle-tendon system have shown that muscles (including