<Tr> <Th> FMA </Th> <Td> 9611 </Td> </Tr> <Tr> <Td_colspan="2"> Anatomical terms of bone (edit on Wikidata) </Td> </Tr> <P> The femur (/ ˈfiːmər /, pl . femurs or femora / ˈfɛmərə, ˈfɛmrə /) or thigh bone, is the most proximal (closest to the hip joint) bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs . In vertebrates with four legs such as dogs and horses, the femur is found only in the hindlimbs . The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with the tibia and kneecap forming the knee joint . By most measures the femur is the strongest bone in the body . The femur is also the longest bone in the human body . </P> <P> The femur is the only bone in the thigh . The two femurs converge medially toward the knees, where they articulate with the proximal ends of the tibiae . The angle of convergence of the femora is a major factor in determining the femoral - tibial angle . Human females have wider pelvic bones, causing their femora to converge more than in males . In the condition genu valgum (knock knee) the femurs converge so much that the knees touch one another . The opposite extreme is genu varum (bow - leggedness). In the general population of people without either genu valgum or genu varum, the femoral - tibial angle is about 175 degrees . </P>

Which end of the femur forms part of the knee