<P> Since 2000, taekwondo has been one of only two Asian martial arts (the other being judo) that are included in the Olympic Games . It became a demonstration event at the 1988 games in Seoul, a year after becoming a medal event at the Pan Am Games, and became an official medal event at the 2000 games in Sydney . In 2010, taekwondo was accepted as a Commonwealth Games sport . </P> <P> Taekwondo is characterized by its emphasis on head - height kicks, jumping and spinning kicks, and fast kicking techniques . In fact, World Taekwondo sparring competitions award additional points for strikes that incorporate spinning kicks, kicks to the head, or both . To facilitate fast, turning kicks, taekwondo generally adopts stances that are narrower and taller than the broader, wide stances used by martial arts such as karate . The tradeoff of decreased stability is believed to be worth the commensurate increase in agility, particularly in Kukkiwon - style taekwondo . </P> <P> The emphasis on speed and agility is a defining characteristic of taekwondo and has its origins in analyses undertaken by Choi Hong Hi . The results of that analysis are known by ITF practitioners as Choi's Theory of Power . Choi based his understanding of power on biomechanics and Newtonian physics as well as Chinese martial arts . For example, Choi observed that the power of a strike increases quadratically with the speed of the strike, but increases only linearly with the mass of the striking object . In other words, speed is more important than size in terms of generating power . This principle was incorporated into the early design of taekwondo and is still used . </P> <P> Choi also advocated a relax / strike principle for taekwondo; in other words, between blocks, kicks, and strikes the practitioner should relax the body, then tense the muscles only while performing the technique . It is believed that the relax / strike principle increases the power of the technique, by conserving the body's energy . He expanded on this principle with his advocacy of the sine wave technique . This involves raising one's centre of gravity between techniques, then lowering it as the technique is performed, producing the up - and - down movement from which the term "sine wave" is derived . The sine wave is generally practiced, however, only in schools that follow ITF - style taekwondo . Kukkiwon - style taekwondo, for example, does not employ the sine wave and advocates a more uniform height during movements, drawing power mainly from the rotation of the hip . </P>

What is the philosophy of tae kwon do