Bird feet and legs only a small extension of the cnemial crest. In grebes both a normal patella and an extension of the cnemial crest are found. The fibula is reduced and adheres extensively to the tibia, usually reaching two-thirds of its length. Only penguins have full-length fibulae. 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"
Ligament of head of femur Ligament of head of femur In human anatomy, the ligament of the head of the femur (round ligament of the femur, ligamentum teres femoris, or the foveal ligament) is a ligament located in the hip. It is triangular in shape and somewhat flattened. The ligament is implanted by its apex into the antero-superior part of the fovea capitis femoris and its base is attached by two bands, one into either side of the acetabular notch, and between these bony attachments it blends with the transverse ligament. It is ensheathed by the synovial membrane, and varies greatly in strength in different