When the iron palm threads were lighting up, it caused me to research the subject of blunt and concussive force trauma to the head.
I am always dubious of "facts" thrown around on forums and in martial arts books and magazines when it comes to the effective of martial arts techniques. So I did my research primarily at verifiable medical websites. Along with the facts I will present are my sources for the information. I believe some may find this interesting and worth passing on to their students.
Here are some facts I came across:
HOW CAN THE BRAIN BE INJURED?
In the United States traumatic brain injury (TBI) is a leading cause of death for persons under age 45. TBI occurs every 15 seconds…The leading causes of TBI are motor vehicle accidents, falls, and sports injuries.
http://www.braininjury.com/injured.html
The brain is vulnerable to traumatic damage in two ways. The cerebral cortex can become bruised - contused - when the head strikes a hard object (or a hard objects strikes the head). Or, the deep white matter can suffer diffuse axonal injury when the head is whiplashed without hitting a hard object (or being hit by one). In serious whiplash injuries, the axons are stretched so much that they are damaged.
Cerebral contusions tend to occur at the tips of the frontal and temporal lobes where they bang up against the interior of the skull. Diffuse axonal injury occurs more toward the center of the brain where axons are subjected to maximal stretching.
http://www.livestrong.com/article/19029-blunt-head-trauma-effects/
Symptoms
Symptoms of blunt head trauma can either occur immediately after injury or develop slowly within a few hours or days. Severe symptoms that can arise from head injury include convulsion, changes in the pupils, inability to move one or more limbs, irritability, personality changes, unusual behavior, loss of consciousness, confusion, drowsiness, low breathing rate, drop in blood pressure, lack of coordination, severe headache, slurred speech, blurred vision, stiff neck and vomiting.
Effects
Injury to the head can result in severe damage to the brain. According to the National Institutes of Health, serious head trauma can result in speech and language problems, coma, chronic headaches, paralysis, seizure, changes in sensation, and changes in hearing, vision, taste or smell. In addition, bleeding can occur within the brain, which can exacerbate brain damage.
http://www.emedicinehealth.com/head_injury/article_em.htm
The Power of a Hand Strike
The force of a professional boxer's fist is equivalent to being hit with a 13 pound bowling ball traveling 20 miles per hour, about 52 g's….
American Association of Neurological Surgeons
http://www.aans.org/Patient%20Information/Conditions%20and%20Treatments/Sports-Related%20Head%20Injury.aspx
Deaths in the Ring
Journal of Combative Sport
From 1890 to 2007 1,335 deaths occurred world-wide in a boxing type format:
14 Toughman style fighters
126 training deaths
293 amateur boxers
923 professional boxers
From 1960 to 2007 there were 421 boxing-related deaths. 80% of the deaths were attributed to head, brain or neck injuries.
http://ejmas.com/jcs/jcsart_svinth_b_0700.htm