It is well known that mental fortitude, technique, and physical strength are the factors that contribute to competitiveness in sports. In judo, these factors are sometimes referred to as “shin-gi-tai,” literally meaning “mind, skill, and body,” which are essential elements in competition. Physical strength in particular affects competitiveness. Improving functional elements, particularly physical strength, is necessary for increasing competitiveness. Leg strength is particularly important in many competitive sports, and evidence from a study that observed leg extension during judo throwing techniques indicates 2) that leg extension power likely influences the success of judo techniques. In judo tournaments, athletes must throw their opponent quickly and with force to earn a high score for their throwing technique. Therefore, it is considered that extending the legs quickly and forcefully while performing a throw has an advantage in judo. For example, leg extension is observed in “flipping” movements where athletes extend their lower leg while they support themselves on one leg with their knees flexed and throw an opponent during an uchi-mata. It is also observed in the rapid extension of both legs while throwing an opponent over the shoulder during a seoi-nage. Thus, leg extension is considered to play an important role in both of these movements. Furthermore, because judo practitioners must also react quickly to their opponent’s moves and maintain their posture to avoid being thrown, leg extension power is another important factor in maintaining posture and balance, while being attacked by an opponent. Based on these observations, it is logical to assume that an athlete must have a very high skill level to become an elite judoka.
