Hinge joint best examples of ginglymoid joints are the Interphalangeal joints of the hand and those of the foot and the joint between the humerus and ulna. The knee joints and ankle joints are less typical, as they allow a slight degree of rotation or of side-to-side movement in certain positions of the limb. The knee is the largest hinge joint in the human body. Hinge and pivot joints are both types of synovial joint. A hinge joint can be considered a modified sellar/saddle joint, with reduced movement. Other objects that work like hinged joints are door hinges, closet doors, and dog
Flying and gliding animals Flying and gliding animals A number of animals have evolved aerial locomotion, either by powered flight or by gliding. Flying and gliding animals ("volant" animals) have evolved separately many times, without any single ancestor. Flight has evolved at least four times, in the insects, pterosaurs, birds, and bats. Gliding has evolved on many more occasions. Usually the development is to aid canopy animals in getting from tree to tree, although there are other possibilities. Gliding, in particular, has evolved among rainforest animals, especially in the rainforests in Asia (most especially Borneo) where the trees are tall and widely spaced. Several