Pivot joint Pivot joint In animal anatomy, a pivot joint (trochoid joint, rotary joint, lateral ginglymus) is a type of synovial joint. In pivot joints, the axis of a convex articular surface is parallel with the longitudinal axis of the bone. According to one classification system, a pivot joint like the other synovial joint —the hinge joint has one degree of freedom. Note that the degrees of freedom of a joint is not the same as the same as joint's range of motion. Pivot joints allow for rotation, which can be external (for example when rotating an arm outward), or internal (as
Concrete hinge Concrete hinge Concrete hinges are hinges produced out of concrete, with no or almost no steel in the hingeneck, which allows a rotation without a relevant bending moment. This high rotations are resulting from controlled tensile cracks as well as creep. Concrete hinges are mostly used in bringe engineering as monolithic, simple, economic alternative to steel hinges, which would need regular maintenance. Concrete hinges are also used in tunnel engineering. A concrete hinge consist of the hinge neck, which has a reduced cross section and of the hinge heads, which have a strong reinforcement. Freyssinet invented the concrete hinges. Leonhardt