A motion controlling hinge for an orthopedic brace is provided. The hinge includes an actuator secured to one arm, and at least one spring member. As the arm with the actuator pivots in a first direction, at a predetermined flexion angle the actuator applies a force to the spring member, causing the spring member to flex. The spring member exerts a force on the actuator tending to bias the actuator away from the spring member, and tending to bias the arm in a second direction opposite the first direction. A movable fulcrum enables adjustment of a force exerted by the spring member on the actuator. A variety of differently sized adapters are securable to the actuator. The size of the adapter determines the flexion angle at which the spring member first exerts force on the actuator.