Aikido techniques are often referred to as waza, which in Japanese means technique, art, or skill. Aikido training is based on predetermined stances between two partners, known as kata, rather than free-form training. The basic idea of the training is that the person receiving the technique (uke) initiates an attack toward the person applying the technique, the tori (取り) or shite ( 仕手) (depending on the style of aikido) or nage (投げ) (when applying a throwing technique), who neutralizes the attack with an aikido technique.

Uke &Tori

Both parts of the technique—uke and tori—are considered equally important in aikido. Both study the principles of adaptation and blending. Tori learns to blend with the energy of the attack and control it, while uke learns to remain calm and flexible in disadvantageous and unbalanced positions into which tori pushes him. The “reception” of the technique is called ukemi. Uke constantly tries to regain balance and cover his weaknesses (e.g., exposed side), while tori uses position and timing to keep uke vulnerable and off-balance. In more advanced training, uke can apply counter-techniques (返し技 kaeshi-waza) to regain balance, immobilize, and throw tori to the ground.

Ukemi

The word ukemi (受身) refers to the act of receiving a technique. A successful ukemi requires attention to the technique, the opponent, and the surrounding environment. It is an active rather than a passive reception. The fall itself is part of the training, as it is a safe way to execute a technique and return to a seated position in a continuous motion, which would otherwise result in a severe impact or throw (or immobilization through locks). The person performing or receiving the throw must assess uke’s ability in ukemi as well as the physical space surrounding them when they are on the tatami: walls, weapons (wooden tando, bokken, jo), and the other practitioners nearby.

Uke should attack with the strength and speed appropriate to tori’s skill level. For beginners, the attack is much gentler than a real self-defense attack.

Aikido Training Techniques

Boat-rowing exercise (船漕運動 Funakogi undō) / Rowing the boat (取り船 torifune). This technique teaches the use of the hips rather than relying on the muscular strength of the arms.
First teaching exercise (一教運動 Ikkyo undō) trains students to enter with both hands in front in the tegatana position.
Body change (体の変更 Tai no henko) changes the direction of the impending attack.
Seated breathing method (座技呼吸法 Suwariwaza kokyūhō) / Breathing action (呼吸動

作 Kokyūdōsa) / Breathing belly method (呼吸丹田方 Kokyūtandenhō).

Breathing plays a crucial role in the execution of all aikido techniques. Furthermore, breathing should be coordinated or in sync, as tori’s movements must align with the direction and force applied to his wrists by uke.
Initial Attacks

Most attacks in aikido resemble sword strikes. Aikido techniques are usually applied as a defense against an attack. For this reason, students of the art should learn to launch various types of attacks. Although attacks are not studied as extensively as in striking-based arts, e.g. karate or Tae Kwon Do, genuine or real attacks (a strong strike or a hold to immobilize) are essential for studying the correct and effective application of a technique.

Many aikido strikes (uchi) often resemble cuts made by a sword or other bladed weapons, suggesting that these techniques were intended for combat with weapons. Other techniques that clearly appear to be punches (tsuki) are treated as strikes with a knife or sword. Kicks are generally reserved for more advanced variations because being knocked down by a kick is particularly dangerous, and because kicks (especially high kicks) were rare during combat during the feudal period in Japan.

Basic strikes 

Front-of-the-head strike (正面打ち shōmen’uchi), a vertical strike delivered with the outer edge of the palm, like the edge of a knife. During training, this strike is usually aimed at the forehead for safety reasons. The most dangerous targets for such a strike are the bridge of the nose and the sinus cavity.
Side-of-the-head strike (横面打ち yokomen’uchi): a diagonal strike with the outer edge of the palm, like the edge of a knife, to the side of the head or neck.
Chest thrust (胸突き mune-tsuki): a punch to the chest. Specific points on the chest are the chest, the abdomen, and the solar plexus. There is also the middle punch and the low punch.
Face thrust (顔面突き ganmen-tsuki): a punch to the face. Same strike as the middle punch.
Sword-taking (太刀取り tachitori): Defending against an attack with a sword or bokken, usually for advanced practitioners.
Knife-taking (短刀取り tantōtori): Defending against an attack with a tantō, usually a wooden one.
Staff-taking (杖取り jōtori) Defending against an attack with a jo. Defending against an attack with any wooden weapon is called botori (棒取り) or tsuetori (杖取り).

• Specifically, beginners usually practice grappling techniques because they are safer, but also because the sensation of energy and power in a hold is more distinct than that of a strike. Some of these grappling techniques historically stem from situations where the defender is immobilized and attempts to pull the weapon. They could apply such a technique to free themselves and, in turn, immobilize or strike their opponent.

  Single-hand grab (片手取り katate-dori): one hand grabs one wrist.
  Both-hands grab (諸手取り morote-dori): both hands grab one wrist. Same technique as “single-hand double-handed grab” (片手両手取り katateryōte-dori)
  Both-hands grab (両手取り ryōte-dori): both hands grab both wrists. Same technique as “double single-handed grab” (両片手取り ryōkatate-dori).
  Shoulder grab (肩取り kata-dori): grabbing the shoulder. “Both-shoulders-grab,” grabbing both shoulders, is called ryōkata-dori (両肩取り). Usually, this technique is combined with a strike to the head, as in the Shoulder grab face strike (肩取り面打ち kata-dori men-uchi).
  Chest grab (胸取り mune-dori or muna-dori) involves grabbing the fabric in the chest area. This is the same technique as the “collar grab” (襟取り eri-dori).
  Rear chokehold (後ろ裸絞 ushiro kubishime)
  Rear both shoulders grab (後ろ両肩取り ushiro ryokatori)
  Rear both wrists grab (後ろ手首取り ushiro tekubitori)

Aikido Techniques

Diagram of ikkyō, or “first technique.”

Yonkyō has a similar mechanism, although the upper hand grasps the arm rather than the elbow.

Taking into account all of aikido’s techniques, this art recognizes over 10,000 techniques. Many techniques originate from Daitō-ryū Aiki-jūjutsu, but others were created entirely by Morihei Ueshiba. The exact terminology for some of these may vary from school to school. The names listed below are terms used by the Aikikai Federation. It should be noted that although the names of the first five techniques are numbered, they are not taught in order everywhere. Aikido shares several techniques with judo (e.g., drop throw), which can be considered a “cousin” of aikido since they share common roots with jujutsu.

• First teaching (一教 ikkyō) ude osae (arm pin): using one hand on the elbow and the other near the wrist, you guide uke to the ground. This grip also applies pressure to the ulna of the wrist.
• Second teaching (二教 nikyō) kote mawashi, a rotating wrist lock that applies torque to the shoulder, causing intense pain to the nerve. (In the ura style, there is the Z-lock, which is a wrist lock that brings the wrist to the center of the axis.)
• Third teaching (三教 sankyō) kote hineri, a rotating wrist lock that directs the force upward through the entire arm, elbow, and shoulder.
• Fourth teaching (四教 yonkyō) kote osae, a grip similar to that of ikkyō, where both hands grasp the forearm. The finger locks (from the palm side) rest on the radius of the person receiving the technique against the periosteum of the forearm.
• Fifth teaching (五教 gokyō) kama kote, visually similar to ikkyō, but with a reversed wrist grip, a moderate rotation of the shoulder and arm, and downward pressure on the elbow. It is usually used to disarm a knife or other weapons.
• Sixth teaching (六教 rokkyō) or Elbow arm-barring pressure (肘極め押さえ hiji kime osae)
• Arm-spraining second teaching (腕挫二教 ude hishigi nikkyo) an elbow lock typically used to defend against knife thrusts or straight punches.
• Four-direction throw (四方投げ shihōnage) The arm is folded behind the shoulder, thereby locking the shoulder joint.
  Forearm return (小手返し kotegaeshi) an outwardly rotating wrist lock that stretches the extensor muscle.
• Breath throw (呼吸投げ kokyūnage) a general term used for various types of techniques that do not use joint locks like other techniques.
• Entering throw (入身投げ iriminage) throws in which tori moves into the space where uke is located.
• Heaven-and-earth throw (天地投げ tenchinage) starting with ryōte-dori; and moving forward, tori sweeps with one hand low (earth) and the other high (heaven), causing uke to lose balance and making it easier for him or her to fall.
  Hip throw (koshinage) is the hip throw of aikido. Tori lowers his hip below that of uke, then twists and lands uke at the desired point.
• Figure-ten throw (十字投げ jūjinage) or figure-ten entanglement (十字絡み jūjigarami): a throw that locks the shoulders together (The Japanese character for the number 10 is shaped like a cross: 十).
• Rotary throw (回転投げ kaitennage): The tori sweeps the arm backward until it locks into the shoulder joint, and then applies forward pressure to throw the opponent.
• Corner drop ( 隅落 Sumi otoshi)
• Arm entanglement (腕絡み udegarami)
• Shoulder drop ( 背負落 Seoi otoshi)
• Body drop ( 体落 Tai otoshi)
• Large Hip ( 大腰 O goshi)
• Shoulder wheel (肩車 Kata guruma)