The femur is the thigh bone of the human body, and a long femur is a relatively good phenomenon that complements the overall height of the body. The body’s height is determined by the length of the lower limbs, the size of the pelvis and bones, and the length of the spine together. People with long femurs have a certain advantage in height, but there are certain standards of height for different countries, different ethnic groups, different genders, different ages, and different genetic factors. If the overall height is within the normal range, it proves that the height is normal. If the overall height exceeds the normal standard, it proves that the height is high. If the height does not meet the standard, the height is short. A long femur only proves that the legs are longer than others, but the overall height still depends on the result at the end of development.