Every day you walk around with your brain moving slowly inside your skull. Just like a soft egg yolk floating in a cloud of bright egg whites.
It only takes a sudden movement or strike, and your brain is moved to one side with an alarming speed. Whether it hits the skull or goes for a spin, the damage can be devastating, as we know from people who have suffered traumatic brain injuries.
But what exactly happens to the brain in that moment of impact? How does it move?
Research that examines the biomechanics of brain injuries typically includes accident-leading crash test doses, mouth-watering athletes or helmets equipped with motion sensors, or human-like models.
Now, scientists have thrown eggs into the mix.
How an egg yolk works when different forces are applied. (Lang et al., Physics of Wetlands, 2021)
As they began as a kitchen curiosity for a team of engineers, with an egg-scraping instrument for home cooks, they set out to study basic physics that governed the movement of soft matter in a melting environment, using an egg to identify the brain .
“As a result of critical thinking, along with simple experiments inside the kitchen, a series of systematic studies came to examine the mechanisms that cause egg yolk deformation,” said biochemical engineer Qianhong Wu from Villanova University in Pennsylvania.
Although their approach was somewhat unconventional, the results of this study aid our understanding of how a soft subject, such as a brain strain, moves and deforms when exposed to side forces. -outside.
The more we know about it and can describe controversial forces affecting the brain, the better researchers can develop safety systems in vehicles, head-to-head design heads for defense, and help sports players improve their tactics to prevent injury.
Inside the skull, the brain rests in a fluid that catches a shock called cerebrospinal fluid.
The most common and mild form of traumatic brain injury (TBI) is concussion, and the term actually comes from a Latin word meaning ‘violent shaking’. But even a single sub-concussive blow to the head is enough to induce changes in how brain cells work, studies have shown.
As for the causes of brain injury, head circumference as a method of brain injury was proposed back in the 1940s. It’s easy to think if you think of a punch to the chin that throws the head back, or someone getting whiplash from a tack.
But there is often confusion about the mechanics of concussion, as there are different ways to measure head effects and use that information to predict brain injury.
Early research efforts looked at the effects of a straight or ‘linear’ line, where the brain is struck in one direction and kicks off the skull. The focus then turned into rotating forces that twist the brain inside the skull.
Needless to say, it’s hard to gauge how the brain can turn in such an impact because we can’t peer within people’s moving heads.
But scientists can still learn something by reshaping the brain, drawing into its cerebrospinal fluid, using similar substances.
In this study, the researchers began by measuring the properties of egg yolks and the outer membrane, so they could measure the pressure on the eggs during work-out experiments. blade, in which there were two positions.
“To damage or deform the egg yolk, one would have to try to shake and turn the egg as quickly as possible,” the study authors write in their paper, so scrambled eggs were -into a clear and controlled vessel of three types of influence.
The team monitored how egg yolks tightened and stretched in different directions with accelerating rotational effects, and also how they changed hard with a direct blow to the vessel.
When an egg-filled rotating vessel was suddenly stopped, the yolk became “horrible” with the false rotating effect, and it took about a minute for the warped yolk to resume its original round shape.
“It simply came to our notice then [decelerating] rotating, has a more detrimental effect on brain function, “Wu said.
The results of this study are parallel to previous research including vehicle crash tests and pendulum head effects, which found that rotating head effects were a better indicator of the risk of traumatic brain injury than serial acceleration.
These conclusions are a reflection of the general consensus that the brain is more sensitive to rotational motion than linear motion.
But that doesn’t mean we should mitigate the effects of straight line altogether, as other researchers have proposed new injury meters that combine measures of linear and rotational head acceleration to be assessing the risk of consensus.
Brain injuries are certainly complex, and unfortunately many go unrecognized. Anyway, with this clever experiment, we will see the brutal effect for ourselves.
The study was published in Physics of wetness.