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Aikido (合気道, aikidō?) is a Japanese martial art developed by Morihei Ueshiba as a synthesis of his martial studies, philosophy, and religious beliefs. Aikido is often translated as "the Way of unifying (with) life energy"[1] or as "the Way of harmonious spirit."[2] Ueshiba's goal was to create an art that practitioners could use to defend themselves while also protecting their attacker from injury.

Aikido techniques are normally performed by "blending" with the motion of the attacker, rather than directly opposing the attack. The aikidoka (aikido practitioner) redirects the attacker's momentum, using minimum effort, with various types of throws or joint locks.[3] Aikido can be categorized under the general umbrella of grappling arts.

Aikido derives mainly from the martial art of Daitō-ryū Aiki-jūjutsu, but began to diverge from it in the late 1920s, partly due to Ueshiba's involvement with the Ōmoto-kyō religion. Ueshiba's early students' documents bear the term aiki-jūjutsu.[4] Many of Ueshiba's senior students have different approaches to aikido, depending on when they studied with him. Today aikido is found all over the world in a number of styles, with broad ranges of interpretation and emphasis. However, they all share techniques learned from Ueshiba and most have concern for the well-being of the attacker.