Pain-induced Aggression: When Anger Intrudes

Ever attacked or chased by a dog when you inadvertently stepped on its paw or tail?

Alright if the case is not that cartoonish, how about…

Ever bitten by your lovely pet dog when you tried to touch it when it was injured? How you reacted? Beat it for misbehaving? And end up its teeth sank even deeper into your flesh? Did you try to understand why it behaved in this way? Why it suddenly turned from an adorable puppy into an aggressive beast?

Yes, it is because of the pain. Such behavior is termed as pain-induced aggression – an instinctive defense reaction of animals to attack the cause of pain.

Likewise, primates like humans do possess such instinct to defend themselves from harms. Here it is more about the psychology of anger. Of course we do not bite when we are provoked or hurt, we are not barbarians. Normally we retaliate in a more civilized way – a verbal counterattack, which may further lead to a physical fight, when tension soars.

From the psychological perspective, anger is a natural and mostly automatic response to pain. It is a kind of aggression results as a psychological defense against threats, hurts and losses, which I call soul’s injuries. The type of pain does not matter. The point is that the pain experienced is certainly unpleasant. As anger never occurs in isolation, i.e. one does not get angry for no reason. There must always be some pain feelings precede, followed by some negative thoughts that trigger anger. Therefore anger is often characterized as a by-product emotion.

From the primitive biological perspective, anger is accompanied by arousal of the nervous system, which the secretion of hormones like adrenaline produces effects throughout the body such as the pupils dilate, the heart pounds, the respiration and blood pressure increase. This phenomenon is better known as the fight-or-flight response, when one is provoked or hurt. In such situation one either chooses to transform the feelings of pain into anger, to defend himself by retaliating against the target that causes the pain; or to avoid and leave, in pain. The latter often results one in misery, who suffers the pain alone.

Sometimes you may wonder: “What on Earth makes him so pissed off with my words? I was just saying… “, well think again. You might have inadvertently touched his wound lying secretly under his soul. When someone loses his temper, when someone is throwing tantrum at you, bear with him, for he is feeling pain. He needs to be understood and accepted. To ease his pain, you may apply the “Taijiquan” philosophy – to conquer hardness with softness. Try to understand the cause of his pain and show your sincere concern and care, that would resolve the tension quicker. When his emotion is calmed after feeling understood and accepted, he would probably regret his misbehavior a moment ago.

Lastly, not forgetting about yourself. Sometimes you do feel angry of someone or something don’t you? When you become the sensitive, easily irritated out-of-control one, you should realize that it is very likely because you were once injured, and the wound has not healed yet. It is your animal instinct to defend yourself from the cause of pain. If you are able to figure out your own wounds, then you will be able to cure them more effectively and hence become a better person, with well-managed emotion.

Quoted from Romans 12:20

“But if your enemy is hungry, feed him, and if he is thirsty, give him a drink; for in so doing you will heap burning coals on his head.”

Bone Remodeling

In the previous post, I mentioned about bone remodeling. Now let’s go deeper into how bone tissue is resorbed and formed in this process.

How bone remodels?

Bone remodeling is a lifelong process to replace and reshape bone, that involves coupled activity of osteoclasts and osteoblasts to resorb and form bone at the simultaneous site. Basically a healthy bone remodeling consists of 5 phases: Activation, Resorption, Reversal, Formation and Quiescence.

For a clearer illustration, I’ve referred to some resources and drawn some figures to represent the process.

In Activation phase, mononuclear pre-osteoclasts are attached to the bone surface and fuse to form large (up to 100µm) and multinucleated (up to 50) osteoclasts. The membrane attached to the bone differentiates as ruffled membrane for further action.

During Resorption phase, the osteoclasts acidify the attached interface and slowly dissolve the bone matrix, result in deep cavities (cutting cones). The calcium is then released to blood for various body functions. Osteoclasts diminish when the resorption is complete.

During Reversal phase the resorbed surface is prepared for the subsequent Formation phase. A sugar-rich cement line is produced to help bonding old bone and new bone.

The Formation phase begins when the osteoprogenitor cells (precursors of osteoblasts) appear along the cavities. The cells undergo mitosis and proliferate (increase in large quantity). Eventually they differentiate into osteoblasts. Osteoblasts then deposit unmineralized bone matrix called osteoid at the cavities.

When osteoblasts are encapsulated by the matrix it synthetize, they become osteocytes and regulate the process of bone remodeling. Osteocytes are known as the most abundant cells found in the bone.

Calcification begins few days after osteoid is deposited: the process where osteoid becomes mineralized with calcium and phosphorus, thus forming the new bone.

The bone surface is restored and covered by the protective lining cells, and remains quiescent till the next cycle.

The Wolff’s Law

I’ve been studying biomechanics these few days, and learned another interesting topic about the bone response to stress.

Wolff’s Law, a widely known bone adaptation theory in the orthopedics, was developed by the German anatomist Julius Wolff in 1892:

The form of a bone being given, the bone elements place or displace themselves in the direction of functional forces and increase or decrease their mass to reflect the amount of the functional forces.

According to Wolff’s Law, bone grows in proportion to mechanical stress. A healthy living bone models and remodels in response to the mechanical stress it experiences so as to produce a minimal weight structure that is adapted to the stresses acted on it.

The changes in bone density, size and shape are the work of two specialized bone cells called osteoblasts and osteoclasts, which respectively form and resorb bone tissue. The bone remodeling occurs throughout life. During the process, resorption precedes formation, so as old bone tissue is replaced by new bone tissue. Remodeling can be in either “conservation mode” with no change in bone mass, or “disuse mode” with a net loss of bone mass characterized by an enlarged marrow cavity and thin cortex. The latter leads to osteoporosis, results from either excessive resorption or inadequate formation. The bone modeling occurs during growth and healing. Unlike remodeling, the osteoblasts predominate the activity (formation) with a net gain in bone mass.

Dynamic mechanical loading causes bones to deform or strain; the larger the loads, the greater the strain. When strain exceeds the remodeling threshold, bone remodeling occurs in conservation mode with balanced resorption and formation. When strain exceeds the higher modeling threshold, the bone modeling occurs, with bone density and mass increased. Disuse mode remodeling is triggered when strain stays below the remodeling threshold, induces a slow loss of bone.

A physically active individual tends to develop denser and more mineralized bones, particularly at the stressed sites. For example, a tennis player has a stronger and denser radius at the racquet-holding arm than the other arm due to the repetitive high stresses exerted on it. Likewise, a trained runner has an increased bone density at the lower extremity due to the high-impact of the running motion. Interesting to note that a competitive swimmer who spends a lot of time in the water however may have less dense bones than a sedentary individual as the buoyant force exerted on the body has counteracted the body weight (gravity).

The law also explains why astronauts suffer from a kind of bone-loss similar to osteoporosis after a long stay in space. Due to the microgravity, the floating human body undergoes a weightless and almost immobile condition. Since no weight is acted on the skeleton and the body do not have to fight the gravity to move about, the bone mass diminishes, hence the strength and the bone mineral density decrease. Bedridden patients and individuals who lead a sedentary or inactive lifestyle tend to have a decrease in bone mass too as a result of reduced mechanical stress and weightbearing activity. The bones become more susceptible to fractures.

In many traditional Okinawan karate-do and Chinese martial arts, body conditioning is crucial as part of the training routine to strengthen muscles and bones, as well as to elevate the pain threshold. Uechi-ryu karate-do emphasizes conditioning on knuckles, forearms, abdomen, tips of toes, dorsal feet, shins, thighs and calves by repetitively blocking and striking the areas to produce slight trauma to them. Other practices like rubbing, knuckle push-ups, rolling a stick on the shin are formulated for conditioning purpose as well. The principle founded by the ancient Chinese masters is the same as the Wolff’s law theory: the bones become denser and stronger after bearing a long period of dynamic mechanical loadings provided by the body conditioning, thus minimize the possible injuries caused by training and sparring.

However, if the applied mechanical loadings are beyond the power of (re)modeling, it leads to fatigue or stress fractures. This problem is very common to athletes who run and jump on the hard surfaces such as distance runners, basketball players, and ballet dancers. The most common affected bones are femur, tibia, navicular and metatarsals. Similarly, martial artists who overtrain themselves may encounter the same problem, when the stresses applied to the bone exceed the bone’s ability to adapt. Therefore it is important for martial artists to ensure the training is done within safe bounds.

Corpus Luteum

While responding to a sparring injuries topic in a martial art forum, I learn about this corpus luteum and I find it an interesting knowledge, so I decide to blog it for better memory, and maybe can share with some readers?

In the menstrual cycle of humans and great apes, the corpus luteum (yellow body in Latin), a temporary endocrine structure, is formed by the remainder of the follicle after the ovulation. Its main function is to secrete the progesterone to maintain the pregnancy if fertilization occurs.

Basically a menstrual cycle of a female human (estrous cycle of animals) can be divided into 4 main phases, which are the menstruation, the follicular phase, the ovulation and the luteal phase. During the follicular phase (preovulation), the secretion of FSH (follicle-stimulating hormone) stimulates the development of several follicles in the ovary. Each follicle contains a oocyte or ovum but normally only one ovum is mature enough to be released during the ovulation. The luteal phase is the second phase of the menstrual cycle and is also known as the post-ovulation. Averagely it starts on the 14th day of a normal 28-days menstrual cycle and lasts for 10 to 14 days. During this phase, the progesterone produced helps to thicken the lining of the uterus or endometrium for implantation and is essential to support a healthy pregnancy.

When the egg is not fertilized, the corpus luteum starts to decay and eventually the production of progesterone stops. The lining of the uterus is then shed off the uterus wall due to the drop of the progesterone level and expelled through vagina during the menstruation.

When the egg is fertilized, the embryo secretes the HCG (human chorionic gonadotropin) to signal the corpus luteum to continue producing the progesterone for maintaining the thick lining of the uterus. The progesterone production by corpus luteum lasts for 10 weeks after ovulation, and eventually the placenta takes over the job to produce progesterone through the end of the pregnancy.

The decay of the corpus luteum leads to the formation of corpus albicans (white body in Latin), which remain as the fibrous scar tissues in the ovary.

Most females know the harms caused by the intense exercise during menstruation but only a little of them are aware of this luteal phase. During the luteal phase, intense exercises such as running, weight-lifting, and other abdominal exercises should be avoided as they instantly rise the abdominal pressure. High abdominal pressure is likely to cause the rupture of the mature corpus luteum. Occasionally, the ruptured site may bleed, resulting in abdominal pain or some signs of hemorrhage. If the ruptured site is capillary-rich, it may lead to massive internal hemorrhage, and cause the hemorrhagic shock or even death; anyway, this kind of case rarely happens.

In my opinion, this is also a potential injury for the female karate-do practitioners, who train for jiyu kumite (free sparring) but so many of them are not aware of it. The impact of a forceful punch or kick in the abdomen instantly rises the abdominal pressure, leading to the rupture of the corpus luteum.

I hope more female sports and martial art enthusiasts will realize the fact and take necessary precautions. After all, prevention is better than cure.

You may find out more here about other potential injuries obtained from the karate kumite training.