Jujitsu is not recommended in those with any physical injury. Practicing jujitsu with an injury has the potential to worsen the injury and prevent healing.
While the effects of jujitsu have not been studied, jujitsu is practiced by millions of people across the world today.
People generally learn jujitsu by observing people that already practice it and imitating their form. These forms include joint locking techniques, take-down techniques, throwing techniques or a combination of take-downs and joint-locks. The strikes are usually targeted to a vulnerable area of the body to make the opponent lose their balance.
The movements of jujitsu tend to be of a circular in nature. The movements attempt to take advantage of the opponents' openings or weaknesses.
Jujitsu is primarily a martial art that does not emphasize the use of weapons. However, small weapons such as the Jitte (truncheon), Tanto (knife), Ryofundo Kusari (weighted chain) and Bankokuchoki (knuckle-duster) can be used in combat.
There are four different systems of jujitsu: the fighting system, the practical system, the duo system and finally combat jujitsu. The fighting system is the most popular system practiced. This system includes three phases: striking only, striking, grappling, and throwing and finally ground-fighting such as chokeholds. In the practical system, two defenders are surrounded by four attackers from four corners. The defenders are given points based upon their effectiveness, oversight, and control of the situation. The defender with the highest amount of points at the end of the match is the winner. The duo system involves contestants demonstrating their defensive techniques. The participants are given points for their effectiveness. There are four groups of five attacks. Combat jujitsu is the system that has been most recently developed in the United States. In this system of jujitsu, two opponents compete and the winner is determined by who fails to defend themselves or rather who is less successful at warding off their attacker. These matches generally last approximately two to three minutes.