This book introduced firstly a new method for analyzing the human lower limb during complete gait cycle by taking into considerations the existed weights and lengths of human lower limb segments, the ground reaction forces and the lower limb joints angles during complete gait cycle. The results are useful to calculate the induced forces and torques at the the lower limb joints at any moment during gait cycle from heel strike to toe off. The second part imposed the modeling and analyzing of the artificial four bar knee joint and making modifications on the initial compression of the assistant...