An Anatomical Analysis of The Weaknesses of the Human Body

 By: Anthony T. Ngo


Although this essay will cover some basic weaknesses and how to target them, it is in no way a compilation of the myriad of several weaknesses located throughout the human body. Due to the actual complexity and length of the topic, the information is meant to be informative and concise, but not a full definition. It is also important to note that some of this material is also dangerous due to the risk of bodily harm and/or fatalities, and should not be demonstrated without instructor’s guidance, practice, and for some maneuvers, at “last-resort”.

“The ultimate aim of martial arts is not having to use them.”-Miyamoto Musashi, Go Rin No Sho (The Book of Five Rings)

It is one’s knowledge of personal strengths and weaknesses combined with those of one’s opponent that establishes a firm foundation for a successful strategy. When engaging an opponent in combat, whether it is under circumstances of spontaneous necessity or intended for codified practice, one’s form, power, accuracy, and instinct are among the most valuable variables to consider when determining survival or victory. However, to achieve the maximum potential of each attack and defense, an increased comprehension of human anatomy is required for the execution of each maneuver.

Throughout the history of martial arts, practitioners have managed to create a series of techniques, such as Chinese Qigong, where their bodies are forced to endure a series of harsh stimulants, resulting in the body to then repair and, most importantly, adapt to different forces that simulate damage often encountered in combat. This “damage”, or rather, cost, is a result of both receiving force from the opponent, but also from the fighter’s own body, most often in the form of energy consumption. Some adaptations the warrior would receive from this type of training include the hardening of the bones, strengthening of the muscles and an increase in flexibility, endurance and reaction time among other benefits. While this type of training will prove advantageous to one’s performance in combat, due to the common frailties developed through the history of human evolution, many areas of the body still remain as effective targets.

No matter what martial art, how many arts practiced, or the experience of an opponent, it is near impossible for a fighter to evade the confines of both physics and their personal anatomy. For example, Wolff’s Law states that the bones of a human, and other organisms, will adapt to the loads that it is placed under. This means that as bones are stressed, they will remodel themselves, increasing their mass and density, to become harder and more resistant to certain stimuli. As demonstrated by martial arts such as Muay Thai, where practitioners would strike hard surfaces repeatedly with their limbs, primarily with the leg’s shin, martial artists have managed to apply Wolff’s Law into their own combative training exercises, toughening and increasing the mass of their bones to resist fracture in real combat and competition. Other Chinese martial arts use Iron Body training, or Qigong, where limbs are repeatedly struck against hardened surfaces such as bags of gravel or sand to condition the body, but more importantly, also the mind. Thai boxers manage to eventually deaden and lessen the pain that accompanies the harsh training and combative style, a similar attribute that accompanies the disciplined mind of Shaolin monks, with many masters capable of breaking solid iron with their hands and head.

However, although the osteoblasts, cells that are responsible for bone formation, do strengthen the bone by repairing micro-fractures with more matter (referred to as cortical remodeling), it does not modify the material that the bones are composed of, nor does it make the bones fully invulnerable to its original weaknesses. Although bones have a very high compressive strength, at approximately 170 MPa, a property gained primarily from the compound, calcium phosphate, it also has the weaker attributes of having low tensile, torsion, and shear stress strength, albeit bones that had undergone intense training would be more resistant to those forces. These weaker qualities of human bones, which are especially prominent in long-bones, are further exposed when they absorb a vertically striking force horizontally, a scenario often seen in attacks where the inexperienced victim would cower and cover their face and vital areas with their arms, most likely resulting in the opponent, or assailant in real applications, fracturing the defender’s arms, and undoubtedly ending in debilitating pain for the victim. The damage that can potentially be done by this maneuver may be extremely effective for martial artists who are capable of producing high levels of static force, making it a powerful and efficient way to quickly dispatch an enemy.

Such a type of offensive attack can be disadvantageous towards the defender; however, it can be easily countered with minimal effort and thought. Israeli Krav Maga, a self-defense system known for its incredible efficiency and use in real-world situation, teaches a theory referred to by some as “bursting”, where instead of shrinking and retreating from an oncoming attack, the defending fighter instead uses momentum and mass energy produced by the legs to propel themselves towards the opponent. Although seemingly counterintuitive to “walk into” the strike, by closing the distance between one’s self and the attacker, not only would ranged strikes be rendered obsolete, but because both speed and velocity are both determined using the distance covered by the striking limb (in elapsed time), reducing the distance reduces the potential damage that could possibly be done by the aggressor. Together, knowing the effects of physics upon attacks and their power as well as understanding weaknesses of both one’s opponent and one’s self can prove greatly beneficial in combative scenarios.

Often, many martial artists practice to improve the strength and power they can produce in their strikes and defenses. However, other martial artists, such as those who are smaller and quicker, might take advantage of their agility to instead focus on the accuracy of their strikes, primarily on possibly the most vulnerable, and sensitive, areas on the body. For example, styles such as styles such as Boxing or Taekwondo focus in drawing power from “kinetic linking”, a technique where energy is increased and multiplied by the locking or “snapping” of the muscles of the body, primarily transferred through some of the strongest muscles such as the legs, hips, and shoulders. Conversely, “weaker”, or rather, softer, martial arts such as Wing Chun focuses on speed, accuracy, and most popularly, simultaneous attack and defense combined with rapid strikes directed towards the weakest areas of the body to maximize the potential damage delivered by the attacker.

One popular target for these types of fighters would most probably be the knee joints, due to the fact that, like many other joints, knees are only able to bend in one direction, and are unable to bend forward past 180 degrees or laterally in any angle without causing damage to the ligaments, muscle, and cartilage. A moderate, but accurate, strike to the knee can incapacitate an opponent quickly due to the massive amount of pain that can be applied. The elbows, similarly to the knees, can also be targeted in a similar manner, sometimes applied in the form of an “arm-bar”, where the attacker is able to use the arm’s length as a lever. The physics behind the maneuver puts the fulcrum at either behind the elbow, which locks the arm in place to be used as a lever, or behind the shoulder, which then creates fulcrum points that load the arm, most possibly to points where the arm can dislocate or break or the muscle and ligaments may tear. This type of damage is practically irreparable, and will most usually leave the opponent’s arm damaged long-term. The weakness of joints is near universal, as there are nearly no joints that are able to bend a full 360 degrees (with minor cases of flexibility), and enough load on any joint, even the small fingers or even as vital as the neck, will often cause an opponent severe pain and can potentially end a fight quickly. A combination of an application of levers, which is most useful for joints, locks, and the natural characteristic of a joint’s maximum load it may bear is vital to survival in self-defense circumstances.

The five senses of the human body are recognized by the nervous system, a complex array of nerve bundles interlocked throughout the body, all connected to the central spine and, more importantly, the brain. These nerve bundles are capable of transmitting electronic signals through the usage of neurochemicals, such at sodium, at a speed of about 100 m/s; however, unlike touch, the speed of pain is instead at a slightly faster speed at 0.61 m/s. Although these nerves are essential for the control of one’s body, as well as the communication of vital information that may affect an organism’s survival, such as pain, the nature of the nervous system can be sinisterly applied to final resort situations.

Whether it is professional fighting, situational sparring, or real-world applications, many fighters and martial artists have experienced a difficulty of breathing subsequently to receiving a strike to the chest. Commonly called “getting the wind knocked out of you”, the sensation is due to an attacker adding pressure onto the Solar Plexus, a complex network of nerves located in the abdomen, at the end of the sternum, which then results in a spasm of the diaphragm, an organ located under the lungs that raises and lowers to either fill the lungs with, or expel them, of air. When the diaphragm spasms, although the lungs are still able to contract and expand to allow the fighter to breathe, the spasm in combination with the pain as a result of the strike makes it difficult for the lungs to fill with air, resulting in a momentary difficulty of breathing for the fighter. In real-world applications, this type of attack can temporarily incapacitate an assaulter and allow victims to gain an upper hand, as the attacker will have difficulty fighting, or fighting back, as a temporary lack of oxygen can cause a weakness and possibly a knockout in the assailant.

However, although attacks that can incapacitate an attacker are important in self-defense, in a few rare circumstances, the “victim” will have little option left but to critically injure an assailant under a dangerous threat. Located in the neck, adjacent the carotid artery and the jugular vein, the Vagus nerve—also referred to as the Pneumogastric nerve—is a crucial nerve that acts in part to control sensory, motor, and secretory functions, and most importantly handles the heart and the rate of its contractions, among other vital organs. As previously mentioned, nerves communicate information, such as pain, through sodium channels. Under the circumstance that the nerve would be struck with sufficient force, nerve cells would immediately respond by flaring sodium through the channels rapidly, sending the signal of intense pain to the brain at speeds nearly undetectable by the defending fighter. The brain then responds using those same sodium channels, shutting down several vital organs and slowing the heart down significantly to a dangerous rate, even stopping any contractions at all, resulting in asphyxiation of the body and death. The Vagus nerve is, however, difficult to strike by inexperienced fighters, and will often leave the attacker vulnerable to any counterattacks should the initial attack fail or has no result. Although nerves and sodium paths may be used for this purpose, a direct strike to the heart may be more effective in some cases. Chinese Kung-Fu includes a palm-heel strike to the left side of the chest, a direct strike to the heart, and with sufficient force, will shut it down as well. Tae-Kwon-Do’s “signature” side-kick focuses the force of the kick into the “blade-edge” of the foot, which can also be applied into the left ribcage, where significant force will also potentially cease the heart’s contractions, hastily ending a fight that can prove to become threatening and dangerous.

Besides nerves, there are other miscellaneous vulnerable areas within the body. The trachea, or more commonly known as the windpipe, is a lengthy tube of muscle and cartilage (pseudostratified columnar epithelium) that is used for the passage of air from the outside into the lungs. The cartilage holds the pipe open to allow for a clear, steady passage of air, and a mucus lining aids in filtering the air passing into the lung by trapping particles, which are then transferred back up by cilia. Although the trachea is essential in the process of breathing for humans, it is also blatantly exposed, and easily damaged. It takes approximately 80 pounds of pressure, equal to crumple an empty can of soda, to crush the trachea. Upon collapsing, smaller blood vessels begin to seep into the lungs, and with a smaller diameter combined with the pain, breathing becomes many times more difficult, and the volume of air that could be used by the body declines due to the displacement caused by the blood. Because of the obvious applicability of the trachea’s weaker design and the anatomical dependence on the windpipe to receive oxygen for function, the windpipe makes a valuable target for the defending fighter, although the strike may mortally maim or kill the aggressor, leaving it, like many other strikes, undesired except under cases of last resort, but nonetheless imperative for survival.

A full understanding of the considerable complexity of human anatomy is incredibly difficult to achieve as a sole goal, let alone use it as the base for all martial art defenses. It is also important to note that opponents will always vary in their experience, strength, and resiliency, meaning weaknesses may not be applicable, or less effective. Altogether, although the analysis of human anatomy may be extremely useful in a myriad of circumstances, survival and victory will not solely depend on knowledge alone, but also the skill, devotion, and most importantly, the fighter themselves.


Long, Hei. Dragon’s Touch. Paladin Press, 1 July 1983. Print

“Hand and Body Conditioning (Hardening) in Martial Arts: Preparing Your Body for Combat.” Hand and Body Conditioning for Martial Arts. N.p., n.d. Web. 21 June 2011.

Brogan. “Krav Maga Pressure Points – Military Hand to Hand Combat Guide.” Scribd. N.p., n.d. Web. 07 Sept. 2012.

Smith, Dan. Bone Forging. Lakewood: 1992. Print.

Dickason, Dennis. Breaking-One Aspect Of The Martial Arts: 1985. Print.

“Celiac Plexus.” Wikipedia. Wikimedia Foundation, 09 May 2012. Web. 07 August 2011.

“How to Properly Execute a Vagus Nerve Knockout?” Yahoo! Answers. Yahoo!, n.d. Web. 07 August 2012.