The femur is located between the pelvis (hip bone) and the knee. It is the only bone in the human thigh and comprises half of the hip joint and half of the knee joint.
The femur bone is the strongest and longest bone in the human body, and it supports the weight of the entire body during movement, such as standing, walking, running and jumping. All of the muscles from the lower leg to the lower back run along the femur. Since the femur forms a ball-and-socket joint with the pelvis, allowing for a full range of motion, these muscles work in a synergistic manner to support the entire skeleton for movement.