Analysis of a novel above-knee prosthesis based on EMG

A novel six-bar mechanism above-knee (A-K) prosthesis is introduced. Compared with four-bar mechanism, it has more instant inactive joints, thus it maintains more stability during the standing phase. Through Complex Penalty Method and computer simulation, the knee joint movement during swing phase can closely follow the corresponding track for a normal subject. Meanwhile, surface electromyography (EMG) signals of five young, physically-fit subjects (two males and three females) are recorded. Through comparing peak-to-peak of quadriceps signals among five subjects during three different phases (sitting, standing, running), it is found that the peak-to peak in running state is the highest and the one in sitting state is the lowest. In this text, the variation of frequency and RMS for quadriceps confirms that different movements lead to different frequency and RMS.