Femur Femur The femur (, pl. "femurs" or "femora" ) or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. 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. The femur is the only bone in the upper leg. The two femurs converge medially toward the knees, where they articulate
Eolambia is expanded forwards. Like the humerus, the femur is bowed, but outwards. However, characteristically, the bottom half of the femur is straight. The fourth trochanter, located halfway down the femur, is vertically tall and triangular, similar to "Probactrosaurus", "Gongpoquansaurus", and other iguanodonts but dissimilar to more basal ornithopods. Like the ulna and radius, the tibia and fibula have straight shafts, and they articulate with each other; a roughened projection on the bottom of the fibula fits between two bulb-like condyles located just behind the cnemial crest on the bottom end of the tibia. The top of the tibia is rough,