Abstract: An articulated mechanical joint for use in knee apparatuses such as knee braces allowing extension and flexion of the wearers' knees to which the braces are applied, artificial articulated knees of leg prostheses, and the like, comprises a pair of elongated femoral and tibial links edgedly facing each other at one end and a pair of cheek plates one on each side over the links. Each cheek plate is pivotally connected to both links up their edgedly facing ends, one plate independently of the other so that each end of each link has two pivots connecting to the two plates. The pivot axes of the different pivots are so positioned that the rotation axis of the pivotally connected links is so shifted as to reproduce accurately the complex rotation of the knee. Moreover, because of the strengthening cheek plates, the mechanical joint provides a better resistance to sidewise motion of the tibia and femur of the leg.