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
The Crooked Hinge from a locked library. Dr. Gideon Fell investigates and reveals the surprising solution to all these questions. This novel was fourth in a list of the top ten "impossible crime" mysteries of all time (created by noted locked-room mystery writer Edward D. Hoch). The Crooked Hinge The Crooked Hinge is a mystery novel (1938) by detective novelist John Dickson Carr. It combines a seemingly impossible throat-slashing with elements of witchcraft, an automaton modelled on Maelzel's Chess Player, and the story of the Tichborne Claimant. It was dedicated to fellow author Dorothy Sayers "in friendship and esteem." In a poll of