Development of the above-knee prosthesis started with a goal to solve the problem of climbing the stairs in a biologically inspired way for people with transfemoral amputation. During the course of several years, different prototypes were developed and subsequently tested. The last prototype has proven that the best gait movement is achieved with a prosthetic leg that has separate hydraulic actuators in the knee and ankle joint. Being a prototype, most attention was given to the functionality of the prosthesis. That is why this paper focusses on the redesign and optimization of the prosthetic leg prototype. First of all, a handle was constructed for the purpose of attaching the foot with a prosthesis and a hydraulic cylinder. The lower leg was then redesigned, consisting of two parts, interconnected by a pipe adapter and a pyramid adapter. Two supports were also constructed - a hydraulic unit carrier and an oil tank carrier. Static analysis was performed on the parts using the SolidWorks Simulation module, after which a prosthesis model was assembled.