I am persistently surprised by science and scientists. As we live and breathe, there are thousands of people around the planet quietly and persistently pursuing little veins of knowledge that would struggle to interest the majority of humans. They are intrigued by things that perhaps would never occur to us. They are specialized, focalized, and engaged, but in their own world.
To be fair, their pursuits are likely no more recherche than this little world of workers' compensation in which we strive. Comp, like gravity, is all around and often ignored. But there is perhaps value in the study of our world. Which leads me to woodpeckers. What is the possible general-value result of studying these noisy, little feathered friends?
Earth.Com reports that Woodpecker skulls do not absorb the shock of hammering on trees. Who knew? Why does it matter? It turns out there has been conjecture, or "conventional wisdom" that the structure of the woodpecker skull must provide some manner of "shock-absorbing," or the resulting damage to neurons from that persistent pecking would mean brain damage. The impacts of the movement, accelleration and sudden deceleration, implicate concussion.
But, in 2022, Current Biology published a study that refuted the "conventional wisdom," and decries any notion of a "shock absorbing" skull. The researchers used "high-speed video footage" to test the "deceleration of the brain" in these rapid head movements. They hoped to identify anatomical "shock absorption," but instead found that deceleration of both beak and head demonstrated "no significant difference." If there were some absorbtion, the head would benefit and somehow decelerate less suddenly than the beak.
The study authors concede that their efforts are laboratory and film-related. They note "hypotheses on shock absorption by the woodpecker’s cranial musculoskeletal system remain untested in natural situations." That is, the "real world." It is difficult to imagine how one might study this in the "real world," but it is perhaps possitive that these researchers are focused on any potential flaw or shortcoming in their process.
The scientists went on to confirm that if the shock absorption theory were real, then the birds would not be very effective at penetrating the trees. They concluded that if it were true, "the bird would actually have to peck harder in order to perform successful pecks." The energy consumption necessary for that additional effort would alone lead them to doubt this shock-absorber head theory.
So, with the theory debunked, the question remains, why is this not damaging to the bird brain? The scientists measured the effect of the impact, and found that "the deceleration shock that causes concussion in monkeys and humans is around 103 kPa at the site of impact." This is the threshhold for dangerous trauma and shock. The woodpecker does not suffer brain damage because they "experience only between 40 and 60 percent of this pressure." So, through the study of these birds, we arrive at determinations regarding the severity of head impact and the odds of resulting concussions.
The news is of particular importance for humans as the subject of concussion and preventative measures is addressed. The scientists noted that "engineers have previously used the anatomy of the woodpecker’s cranial skeleton as a source of inspiration for the development of shock-absorbing materials and helmets." While the research does not support that this is harmful or inappropriate, the conclusion seems to be that mimicking such bird anatomy is not likely to prevent human concussion. That reliance has been misplaced.
Why is this important? There is a multitude of opportunities for head injury in the workplace. In a general sense, there is the belief that "5-10% of athletes will experience a concussion in any given sports season." That is significant. Sports involve moving objects, colliding people, and the chance of falls. But, in a less "contact" environment, where would such injury arise?
Eastern Kentucky University notes that the most common causes (all numbered are direct quotes) of workplace injury are:
- A bodily reaction to overexertion (such as when lifting objects or performing repetitive motions), which caused 31.0% of workplace injuries
- Falls, slips, and trips, which caused 27.5% of workplace injuries
- Contact with objects or equipment, which caused 25.8% of workplace injuries
- Transportation incidents, which caused 5.6% of workplace injuries
- Violence and other injuries caused by a person or an animal, which caused 5.0% of workplace injuries
- Being exposed to harmful environments or substances, which caused 4.2% of workplace injuries
The chances of a head injury are notable in 2, 3, 4, and 5 (which are about 64% of work injuries). Some contend that "24% of traumatic brain injuries (TBI) are work-related." Consistent with the University list above, they note these are "most commonly caused by falls, getting struck in the head by falling objects, or motor vehicle accidents."
So, as odd as it may seem for researchers to be studying woodpeckers so assiduously, the real point is that traumatic brain injury is a prevalent issue. While the shock-absorbing skull turns out to not be a path to preventing or ameliorating those injuries, the elimination of that alternative perhaps allows other scientists to formulate and explore different hypotheses.
