A linkage system for transmitting torque includes a central element, an input arm and an output arm. The central element has four sides and a top and bottom. The input arm and an output arm each have a head portion for connecting with the central element and a body portion. The head portion of each of the input and output arms defines a bearing surface having a first radius. The input and output arms engage the central element such that the bearing surfaces of the heads are offset by 90 degrees.