A kick is a physical strike using the leg, in unison usually with an area of the knee or lower using the foot, heel, tibia , ball of the foot, blade of the foot, toes or knee . This type of attack is used frequently by hooved animals as well as humans in the context of stand-up fighting. Kicks play a significant role in many forms of martial arts, such as capoeira, hapkido, hwarangdo, jeet kune do, kalaripayattu, karate, kickboxing, krav maga, kung fu, wing chun, MMA, Muay Thai, pankration, pradal serey, savate, sikaran, silat, taekwondo, tang soo do, vovinam, wushu and Yaw-Yan. Kicks are a universal act of aggression among humans. Kicking is also prominent from its use in many sports, especially those called football. The best known of these sports is association football, also known as soccer.