This paper compares the static performances of two types of antagonistically actuated joints: a revolute (R) joint and an antiparallel-ogram (X) joint. Both joints are equipped with lateral springs and actu-ated with two opposite cables running through the springs. The comparative study is conducted on the basis of their wrench-feasible workspace and stiffness. A methodology is proposed for the optimal design of each joint. Eventually, an R-joint and an X-joint, optimized for the same prescribed wrench-feasible workspace, are compared on the basis of their maximal actuation forces.