The human leg is the entire lower extremity or limb of the human body, including the foot, thigh and even the hip or gluteal region; however, the precise definition in human anatomy refers only to the section of the lower limb extending from the knee to the ankle (called “crus” in Latin or “sura” for the backpart). Legs are used for standing, walking, jumping, running, kicking, and similar activities, and constitute a significant portion of a person’s mass.