How to Bend an “Unbendable Arm”

In his final years, the founder of Aikido was seen to demonstrate many skills that defy the layman’s understanding of physics. Ueshiba sensei reportedly used sen sen no sen and psychic powers to disrupt his opponent’s attacks, threw attackers without touching them, or simply disappeared and reappeared in a safer location.

O-Sensei’s disciples and descendants are unable to repeat his incredible demonstrations. Instead, modern Aikido dojos will introduce ki (life energy) principles to their students with the help of a crude parlor trick: orenaite, or the “unbendable arm”.

Aikido's unbendable arm
Credit: Oscar Ratti

In a typical performance of the unbendable arm, the ki guy will assume a biomechanically superior position, then ask his mark to try and bend his relaxed*, outstretched arm. When the mark finds himself unable to do so, the ki guy attributes his triumph to extended ki.

If you ever find yourself on the wrong end of an unbendable arm, here is a sneaky trick you can use to regain the upper hand. Reposition the ki guy’s hip as shown in the video below, misaligning his spine*, and decreasing his ability to resist your force.

To learn more silly tricks—like tearing a phonebook in half, breaking bricks, or showing your iron body—visit

* Relaxing your muscles does improve your ki flow, and bad posture does impede it. Unbendable arm is a trick because these facts are irrelevant to the feat, not because they are untrue.


  1. thanks for link in this blog. I am wondering if the irreproducible siddhi’s of O-Sensei’s, provided they were real, had anything to do with some sort of meditative training that his followers were not practicing or he did not share.

  2. Holy cow, you can tell it’s been a long day when I struggle to figure out what 4+9 is. Hopefully this isn’t your way of screening out the slower bunch!

    After Priscilla Palmer’s self development list Jenny and I have decided to try to help build the self development community. So we are holding a little contest. I would like to invite you, and anyone else interested, to find out more details at Win a $25 Gift Certificate.

  3. “The Unbendable Arm that Wasn’t.”

    Umm… that isn’t Unbendable Arm. The drawing on your page, attributed to Oscar Ratti, shows the setup for Unbendable Arm (UA). You are not doing UA; you are doing a different “feat of strength”*. UA is about increasing strength, this trick is about decreasing strength.

    This type of test is often used in Applied Kinesiology to test substances held in the hand or mouth (– Strong, the substance is good for you; weak, the substance is bad for you. Bunk.

    Your explanation of how to defeat this specific feat-of-strength is also not correct.

    You said “try it”, and I did, and it is off. I tried it with the distal foot 1/2 inch, 1 inch and 3 inches off kilter. I tried it on one leg, then the other. I tried it a number of different ways to “misaligning my spine”. The deltoid (which lifts the arm) was just as strong in all positions.

    I feel that the young lady in the video had the “right method but the wrong explanation”. Watch her start to push and then take two steps back and then continue to push. Detail = Devil.

    I would say that the key point you made was that there is a technique that “decreases [your opponents] ability to resist your force.” The deltoid’s (or almost any muscle group, or the body as a whole) ability to resist a force can be reduced from the exact same position that that it was strongest in.

    I am not writing to give hell. You are giving these feats-of-strength a ‘good shake’ to see what falls out, and I champion that! But keep shaking this one!

    Good luck,
    Stephen J. Goodson

    * = Is there a name for this trick? I was shown it back in 1991 in Atlanta from a “Magnetic Healer” (poor gal, a story I have yet to write up!). I guess it could be called Undepressable Arm? But that sounds a bit emo’ I think. How about, “severing the strength”!

  4. I met an old aikido master once. I mean this guy must have been in his late eighties. Anyway, he rested his arm on my shoulder and told me to try to bend it. Obviously I could not. Then he told me to put my arm on his shoulder and imagine that my arm was a firehose with water rushing though it. My arm was relaxed but he was not able to bend it. I have also done this with other people and they too could not bend my arm.
    The aikido master then knelt on the floor and asked the rest of us to try to push him over. There were about ten of us and as hard as we tried we could not move him. I would say he has pretty strong ki.

  5. Stephen,
    I realize that this video is merely an unbendable arm demo, not the unbendable arm. My point, in retrospect poorly made, was that ki is not equivalent to biomechanics.

    I have tried the experiment depicted in the video with three other people. One said the hip adjustment made a slight difference, two said it did not.

  6. Hi Chris,
    You are right, the unbendable arm in the video is different and is totally related to biomechanics. The unbendable arm I am referring to is when you are facing the person and resting the back of your hand on that persons shoulder. Then the person tries to bend your arm by pushing down on the arm.
    I will try the experiment you are referring to and let you know how it turns out. Try the unbendable arm and picture that your arm is a firehose with water shooting through it. If you really believe the water is going through your arm, the other person will not be able to bend it. I would recommend standing on flat ground, but if you want to try unbalanced it could be interesting.

  7. Bruce, strangely enough, I have experienced dim mak and performed no-touch throws, but I have yet to meet anyone who could create the unbendable arm solely through the use of ki. Not to say it is impossible.

    Sensei Patrick Parker:

    The Japanese term is orenaite, which means something close to, “The arm that is not to be bent.” Notice that this is not really the same thing as “the unbendable arm.” It is an advisory to not bend your arm – not to be so strong that your arm can’t be bent.

  8. When the man tries it, the two people are face to face, and his elbow is bent. When the woman tries it, she is off at a 45 degree angle and her elbow is not bent. This is retarded. It has nothing to do with the feet or the spine.

  9. Nice post and followup discussions, there are far to many Ki-sters out there with eyes closed to how some physics and biomechanics can be an aid to understanding rather than a threat.

  10. I had an english teacher who was a black belt in karate he showed me how to do the unbendable arm using ki
    it was amazing no matter how hard he tried he couldn’t bend my arm.

  11. I wonder what would happen if your teacher used his unbendable arm as a lever to bend your unbendable arm? I guess that would require an unmovable object as a fulcrum.

  12. It is a common misconception that biomechanics and ki are unrelated. My old teacher, a student a Bruce Francis, would always say what is structurally strong is energetically strong. Ones structure is made from bone and tendon. Bone marrow and tendon are collagen, which with water, creates liquid crystals. The collagen fibers/liquid crystals resemble electromagnetic coils that are aligned along the bone and tendon. A liquid crystal is piezoelectric and can transform mechanical energy into electromagnetic energy, light, etc and visa versa. This is how an liquid crystal display is possible. When collagen is bent there is an electromagnetic response which has been measure by Dr. Robert Becker. (This also explains skins sensitivity as it will send signals to nerves when deformed). The rigidity of collagen is dependent on the spiraling electrical energy flowing through it, hence the visualization of water flowing through the arm. The arm is connected structurally, electrically, and magnetically to the rest of the body. Study alternative energy physics with regards to coils, spin, structured water, and one can only imagine what is possible with the human body.

    Qi-gong concentrates on the development of this system, which among other things will increasing tendon and bone strength. I know Osensi practiced misogi and other meditations religiously and stated that misogi was aikido. Similarly my teacher states that Tai-Chi is advanced Qi-Gong, this can be felt with much practice. Simply sitting with the spine extended in meditation means more electrically energy will be spiraling in the spine.

    A lot is unknown and not taught with regards to energy and the human body.

  13. step back slightly while pulling his arm down at the elbow. as soon as he leans or steps towards you to keep from falling over, his arm will bend, just a natural reaction.

  14. I teach unbendable arm as “an excercise for development of aikido principles” the principles are relaxation and co-ordination. That’s it. I don’t claim that unbendable arm is a magical power or superhuman strength – it is simply an excercise where you try to relax to avoid the arm bending as opposed to tensing your muscles. Unfortunately a huge amount of mis-reporting and myths surround the technique.

    UA is used as a practice excercise for aikido. I used a punchbag when I was boxing and I used makiwara when I did karate. They are all the same – simply excercises or techniques you use to develop your practice and training. For me UA develops concentration, relaxation, co-ordination, focus and meditation.

  15. The unbendable arm is related to standing meditation like I-Chuan where the relaxed arms are held up by “Ki” through tendons. What is Ki? Ki is Chi is charge (at least very related). The dantien/hara when rehabilitated (kung fu) and compressed can hold up the arm with charge like a hydraulic system using piezoelectric effect of proteins of the connective tissue.

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