This paper presents the design phases and modeling of multi axial compliant prosthetic knee joint comprised of rigid and flexible members providing a better performance than traditional spring-loaded rigid multilink joints. Mechanism consists of monolithic compliant five bar incorporating large deflecting flexure hinges, two rigid body representing the upper and lower legs, translational spring and flexure joints simulating ankle motion. Dynamical modeling is studied by integrating pseudo rigid body modeling of small-length flexure hinge method and Lagrange equations under the assumption that link 2 (left base link) is fixed and link 3 is rotated quasi-statically at constant speed. Torsional stiffness of ankle springs is obtained by using MSC Adams simulations. Initial prototype is built by 3D printing the parts using polylactic acid (PLA) filament. Mechanism is potentially suitable for pediatric prosthetic knee systems due to its simple design, versatility and light weight.