It's football season so along with cheers and yelling you will hear a more dangerous sound; the sharp crack of helmet-to-helmet collisions. Hard collisions can lead to player concussions but the physics of how the impact of a helmet hit transfers to the brain is not yet well understood.
A research team has created a simplified experimental model of the brain and skull inside a helmet during a helmet-to-helmet collision. The model illustrates how the fast vibrational motion of the hit translates into a sloshing motion of the brain inside the skull.
Murray Korman, a professor in the physics department at the U.S. Naval Academy, worked with Duncan Miller during the course of a semester to develop the experimental model. To simulate a side collision, the researchers hung one helmet from the ceiling with clothesline and swung the second helmet into the first, like a pendulum. Accelerometers mounted on the helmets recorded the vibrations before, during, and after the hit.
Figuring out simple ways to model a human head inside the helmets was a challenge, Korman notes. Human cadavers were out, and crash test mannequins were too expensive. After reading up on skull vibrations, the team settled on a wide plastic hoop, shaped like the skirt of a bell. "They say that when you get hit, you get your bell rung. No pun intended, but your skull does kind of ring like a bell," Korman says.
The researchers modeled the brain as a brass cylinder cushioned in a slot carved out of open-cell foam that mimicked fluid within the brain cavity. By choosing simple materials the researchers minimized the complexity of their set-up while retaining those elements needed to capture the essential motions of the brain and the skull. They found that their brass cylinder brain sloshed back and forth within the skull much more slowly than the rate of vibration of the initial hit. Building a model is important, Korman notes, because it can help determine how a measurable parameter, like the acceleration of a helmet during a hit, would translate into potentially damaging brain motion. "The ultimate damage comes when the brain hits the side of the skull," Korman says.
Korman says there is still a lot of work to do to improve the model. He hopes in the future to collaborate with biophysicists to incorporate more detailed knowledge of the material properties of the brain and skull. Ultimately, the model might be used to test new helmets designed to better protect the brain from hits. Korman describes futuristic helmets that might crumple on impact like plastic car bumpers, leaving the only bell ringing on the field to be done by the marching band.
The researchers will present their findings at the 164th meeting of the Acoustical Society of America (ASA) next week in Kansas City, Missouri.
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Lexus Hoverboard Gets Off The Ground
- EWG's Little Site Of Horrors
- What May Be Missing From Quantum Computing - A Quantum Middle Man
- New Mars Colony Mission Crowdfunds its Way to the Red Planet
- Predictive Coding Theory: How Our Brains Recognize Faces From Minimal Information
- Gene Therapy For Cystic Fibrosis Shows Beneficial Effect On Lung Function
- "(Maybe) an interesting article - from 1980.De Luise M., Blackburn G.L., Flier J. S.: Reduced activity..."
- "I was just guessing. Wouldn't be at all surprised if you were right. You just have to wonder what..."
- "That stays on course with the humor theme, because homeopaths have never had a citation...."
- "the authors refer to an out of date vision of memristor. The general theory of first, second, third..."
- "You may have gone the wrong way on this one. I think nemo was only making an amusing observation..."
- $4,200 and up: Millions of children's lives saved through government programs
- First trial of gene therapy for cystic fibrosis shows beneficial effect on lung function
- We're not alone, mathematically, but the universe may be less crowded than we think
- Income taxes give a more accurate picture of the value of a college degree
- Human antibody blocks dengue virus in mice