Magnets may make helmets safer | Science News for Students

Magnets may make helmets safer

Repulsive force could reduce impacts, cut risk of concussions
Dec 8, 2014 — 8:26 am EST
football tackle

A new study tests the idea of adding magnets to football helmets to reduce the force of head-to-head collisions.

MATTRADICKAL/FLICKR (CC BY-NC 2.0)

WASHINGTON, D.C. — Adding magnets to football helmets could reduce the risk of concussions, a new study finds. When two players collide, the magnets in each player’s helmet should repel the other’s. This should reduce the force of the collision.

Football helmets now work by dispersing the energy as an impact occurs, explains neuroscientist Raymond Colello. Helmets with built-in magnets could put a brake on an impact before it happens, he says. Colello works at Virginia Commonwealth University in Richmond. He shared his team’s data November 15 at the annual meeting of the Society for Neuroscience.

The magnet idea hasn’t been tested yet in helmets with real players, notes Judy Cameron. “But a lot of thought has gone into it,” she says. Indeed, she adds, the data shown on the ability of the magnets to repel each other “looked extremely promising.” Cameron is a neuroscientist at Pennsylvania’s University of Pittsburgh.

On the field, football players often suffer a concussion. That’s a brain injury that can cause headaches — or even leave a person unconscious. The blow may cause the head to move quickly or come to a rapid stop.

Each year in the United States, there are 100,000 concussions among the nearly 1.2 million people of all ages that play football. Colello wants to reduce this risk.

To do so, he is testing magnets made from neodymium (NEE-oh-DIM-ee-um), a rare-earth element. Rare earths are a group of metals that tend to be soft, bendable and chemically reactive. Magnets made from them are the most powerful ones you can buy.

Colello’s new helmet would hold three such magnets. They would add about 0.45 kilogram (1 pound) to the helmet. A normal football helmet weighs about 1.6 to 2.5 kilograms (3.5 to 5.5 pounds). When placed 0.6 centimeter (0.25 inch) away from each other, two of the magnets (with their like poles facing one another) exert nearly 45 kilograms (100 pounds) of repulsive force.

Colello tested his magnets with the same procedure used to evaluate football helmets. First, he placed magnets on the front of a weight. Then he let the weight drop from various heights onto another magnet. The falling magnets created the same range of impact forces that football players can encounter.

“At 48 inches [122 centimeters], if you dropped a standard helmet and it hit a stationary object, it would create 120 g’s of force,” Colello said. That acceleration is equal to 120 times the force of gravity. “With the magnets, we drop that to below 100 g’s,” Colello says of the collision force. That reduction can be important: Concussions readily occur at impacts greater than 100 g’s.

Colello has ordered customized arc-shaped magnets that can be fitted inside helmets for testing. He plans to send helmeted crash-test dummy heads toward each other down a zip line. When they collide, special sensors called accelerometers will measure the force of the impacts.

Helmets fitted with magnets could reduce the risk of concussions by up to 80 percent, Colello’s data indicate. Adding the magnet technology could also up the cost of a helmet by $50 to $100.

The magnets do attract metallic objects. However, football leagues often prohibit players from wearing jewelry during games.

Another safety concern is whether the magnets are dangerous to have near human heads. Colello says that a 30- to 60-minute magnetic resonance imaging (MRI) procedure produces magnetic fields 10 to 30 times as strong as those in magnet-bearing helmets.

Power Words

acceleration  The rate at which the speed or direction of something changes over time.

accelerometer  An instrument for measuring vibrations or a change in the rate of movement. These sensors typically can measure movement changes in all three dimensions (front-to-back, side-to-side and up-and-down).

concussion  Temporary unconsciousness, or headache, dizziness or forgetfulness caused by a severe blow to the head.

g force    The force of gravity, where 1 g is equal to the average force of gravity on Earth’s surface. That’s 9 meters (29.5 feet) per second per second. It is a unit of measure commonly used to describe the force of acceleration in a moving object.

gravity  The force that attracts anything with mass, or bulk, toward any other thing with mass. The more mass that something has, the greater its gravity.

magnet  A material that usually contains iron and whose atoms are arranged so they attract certain metals.

magnetic resonance imaging(MRI)  An imaging technique to visualize soft, internal organs, like the brain, muscles, heart and cancerous tumors. MRI uses strong magnetic fields to record the activity of individual atoms. 

neuroscience  Science that deals with the structure or function of the brain and other parts of the nervous system. Researchers in this field are known as neuroscientists.

rare earths    (in Earth science) These are a group of metal elements that tend to be soft, bendable and chemically reactive.

Further Reading

S. Ornes. “Football hits the brain hard.” Science News for Students. May 27, 2014.

S. Ornes. “Headers and memory loss.” Science News for Students. June 20, 2013.

A. Pearce Stevens. “Concussions: More than ‘getting your bell rung.’Science News for Students.Feb, 20, 2013.

S. Perkins. “Helmet helper.” Science News for Students.May 15, 2012.