<P> The fibula is reduced and adheres extensively to the tibia, usually reaching two - thirds of its length . Only penguins have full - length fibulae . </P> <P> The bird knee joint between the femur and tibia (or rather tibiotarsus) points forwards, but is hidden within the feathers . The backward - pointing "heel" (ankle) that is easily visible is a joint between the tibiotarsus and tarsometatarsus . The joint inside the tarsus occurs also in some reptiles . It is worth noting here that the name "thick knee" of the members of the Burhinidae family is misnomer because their heels are large . </P> <P> The chicks in the orders Coraciiformes and Piciformes have ankles covered by a patch of tough skins with tubercles known as the heel - pad . They use the heel - pad to shuffle inside the nest cavities or holes . </P> <P> Most birds have four toes, typically three facing forward and one pointing backward . In a typical perching bird, they consist respectively of 3, 4, 5 and 2 phalanges . Some birds, like the sanderling, have only the forward - facing toes; these are referred to as tridactyl feet . Others, like the ostrich, have only two toes (didactyl feet). The first digit, called the hallux, is homologous to the human big toe . </P>

Where do birds feet go when they fly