History’s Strongest Disciple Kenichi- Apachai’s Punch

History’s Strongest Disciple Kenichi- Apachai’s Punch

Now I already know what some of you might be thinking, “Ugh, not another head injury post,” and don’t worry, this might be about a martial arts anime, but it has nothing to do with head injuries. In fact, we are going to be talking about the heart, specifically the electrical conduction system that tells the heart when to contract. The reason as to why can be found in the video below.

If you’re wondering why I didn’t use this for my Head Injuries in Anime, it is because Akisame calls for CPR at the end of the snippet, signifying a problem with the heart. Which of course means that Apachai hit Kenichi in the chest, and not the head. Let me be clear: I am not a martial artist, and while I would love to learn Kendo at some point, I have never taken any classes beyond a few karate classes when I was a little kid. This means I am not going to be talking about a death touch or any sort of fatal martial arts move. What I will be talking about is how Apachai could have stopped Kenichi’s heart during their training.

Biology of the Heart

The heart is a muscle that is about the size of your fist, and it pumps blood around the body. While we cannot consciously control the heart, it is still a muscle and works much the same way as the rest of the muscles in the body. This means that they run on electrical impulses generated by the nervous system. These electrical impulses are generated by changes in the concentration of ions inside and outside of the nerve cell. Any more than this is beyond what is needed to discuss how the electrical system of the heart works.

heart diagram

While the brain does control the heart, it does not actually tell the heart to contract. The heart is autorhythmic, meaning that the heart tells itself when to contract. This naturally translates into a heart rate between 70-80 beats per minute. What the brain does is tell the heart to either speed up or slow down the heart rate.

Vagus nerve– slow down the heart rate

Cardiac sympathetic nerve– speed up the heart rate

Each of these nerves originates from cardiac control centers in the brain stem and are why the heart will continue to beat when the cerebrum is damaged or destroyed, but that is a lesson for another day.

brain diagram

Control of the Heart

If the brain isn’t telling the heart when to contract, then what is? The sinoatrial node is a cluster of specialized nerve cells on the top of the right atrium that tells the heart when to contract.

heart diagram

The sinoatrial node sends out an electrical impulse that travels across the cardiac muscle cells of the atrium causing it to contract and pump blood down into the ventricle. At the same time specialized nerve cells called Purkinje fibers carry the impulse to the atrioventricular node, where the signal pauses for a second. The reason for this pause is to give the atrium time to contract and for the ventricles to fill with blood. In case you are wondering, “Well, won’t the signal travel down the muscle cells to the rest of the heart?”, it can’t because the ventricle is insulated against the electrical impulses from the atrium unless they pass through the atrioventricular node.

The signal leaves the atrioventricular node traveling via the Purkinje fibers all the way to the base and sides of the heart. This is so the bottom of the heart contracts first, pushing the blood up and out of the heart. It is at this point where I would like to use a line I use with my students from time to time: “I could explain this to you 10 different ways, 10 different times, but it is easier to see and understand it.”

Hopefully that answers any questions and clears up any misconceptions you might have. Now we can move a bit closer to what happened to poor Kenichi.


Arrhythmia- it might be a bit of a mouthful, but it is a real scientific term referring to when the heart muscle does not contract correctly. This can range from beating too slow, bradycardia, or too fast, tachycardia, or fibrillation, uncoordinated muscle contractions that cannot pump blood properly. Fibrillation can be further subdivided into 2 types: The first type is atrial fibrillation, where the atria do not contract properly, but the ventricles still work properly. This means that the heart can still pump blood around the body, just less effectively than before. The second type is ventricular fibrillation, where the ventricles cannot function properly, and the heart can not pump blood at all, and can be fatal if left untreated. The causes of arrhythmias are many and highly varied, but there is one that I will be focusing on today, trauma. Yes, an arrhythmia can be trigged by being hit, but there are several conditions that need to be met for this to happen.

Commotio Cordis

Commotio cordis is a rare type of arrhythmia that can occur in males ages 8-18 who are struck in a specific area of the chest. The area in question is the precordium, which is the area of the chest that is directly over the heart.

location of the heart

In addition to the location, the force and timing of the impact are also important. The blow much be hard enough to temporarily cause a small change in the size of the heart, and happen as the heart is resting between beats. A forceful blow at this time causing the cells of the heart to change electrically causing an abnormal heartbeat. Ventricular fibrillation is often the result, and since it is the most dangerous of the arrhythmias, commotio cordis is a very serious condition that can result in death if not properly treated.

While commotio cordis can occur in a variety of sports including martial arts, it is most commonly found in ball sports, where the ball is small in size and launched at great velocity towards the opponent, with the vast majority of events happening in baseball.

commotio cordis

This why you see many little league baseball leagues requiring their players to wear a chest pad when batting. The pad blunts the force of the impact enough to prevent commotio cordis from occurring.

The symptoms of an event start with the impacted individual stumbling forward before passing out with no breathing or pulse, as the heart is no longer working properly. There will also be a lack of apparent injury despite being hit. At this point CPR should begin, followed by defibrillation. Defibrillation is the technical term for shocking the heart with electricity. The shock effectively causes the heart to reboot, like hitting the power button after your computer gives you the blue screen of death. In most cases this is done with an automated external defibrillator (AED).


They are actually pretty easy to use once you have the training, especially the newer versions that walk you through everything including CPR. I highly recommend you get trained on it if you work with kids.

One last thing I would like to mention is that commotio cordis is actually quite rare, with somewhere between 10-20 cases a year, but some medical journals feel it might be under-reported. Even if it is under reported, the condition is still rare: now on to the anime.

History’s Strongest Disciple Kenichi- Apachai


Apachai is a monster of a man at 6’5”, 264 pounds, who also happens to be a master of Muay Thai and Muay Boran. Muay Thai, or Thai boxing, is a modern martial arts system that first crops up in the middle of the 18th century and involves striking with the hands, elbows, knees, and feet. Muay Boran, or ancient boxing, is the original combat art, part of which is used for the basis of Muay Thai. Muay Boran was used by the military and king’s guard, so it includes some techniques that are not found in Muay Thai, including fatal ones.

It is not much of a stretch then to believe that Apachai probably knows some fatal attacks which might include a punch to the chest, and that he accidentally used a fatal attack on poor Kenichi. However, I do not think that was the case, as Apachai is a nice guy, if a little clueless at times. A more logical explanation is that Apachai really doesn’t know the meaning of the word restraint, and he got a little too excited during the training session and forgot to hold back when suddenly punching Kenichi. Let’s remember that Kenichi is 15 at the time, the prime age for commotio cordis, and Apachai is a powerful master of martial arts. A full-strength punch from Apachai, even while wearing pads, more than likely has enough force to cause commotio cordis, which is what probably occurs as Akisame does not find a pulse and orders CPR to begin. In fact, my only problem with the scene is that Akisame would need an AED to revive Kenichi, instead of just CPR. So in the end I will call the Apachai punch scene in History’s Strongest Disciple Kenichi confirmed.


Hajime No Ippo is the gift that keeps on giving now that I have decided to read it from the beginning and this time it is about a boxer that Ippo spars with that has a magic punch. This magic punch is said to temporarily stun the heart, Commotio Cordis anyone.

commotio cordis

Please leave any comments or questions below.



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