Hydraulic cylinders have been selected as actuator in earlier exoskeletons due to low weight and high〓force density. In this paper, we propose a knee exoskeleton using Hydraulic Artificial Muscle (HAM) and〓four-bar knee joint mechanism. The HAM has similar advantages to hydraulic cylinders, but lighter and〓compliance, making it suitable for wearable robot applications. To allow the device to better comform〓to human knee kinematics, a four-bar linkage mechanism was utilized. The human knee biomechanics is〓a combination of rolling and sliding on the condyle, which can be emulated using four-bar linkage. To〓adapt the HAM to the link mechanism, we proposed and Angled Bar as a modification to the existing〓mechanism. The Angled Bar adjusts the torque output and motion range of the proposed device.