Engineering for Sports: Traumatic Brain Injury

As the seasons change from warmer weather to cooler weather, the sports and activities we participate in change too. We swim, bike, run track, and play baseball and softball when it’s warm and the days are long. Cooler, shorter days bring us football, basketball, skiing, snowboarding, and ice-skating. Participation in sports and activities exposes the body to possible injury—broken bones, joint damage, bruises, and even brain trauma. Here’s an eye-opening look at some sport injury statistics.

Sports injuries stats

The National Safety Council provides annual injury facts for a comprehensive selection of sports and activities where the injury was serious enough to warrant hospital emergency department treatment. The information in the table is from the 2017 Injury Facts® chart.

These data are interesting, but let’s take a closer look at school-age children participating in sports. What types of injuries are most common, most severe? The American Orthopaedic Society for Sports Medicine estimates that about 30 million children and teens in the United States participate in sports. It provides the following “Youth Sports Injuries Statistics” on its website:

• High school athletes account for an estimated 2 million injuries, 500,000 doctor visits, and 30,000 hospitalizations each year.
• More than 3.5 million kids younger than age 14 receive medical treatment for sports injuries each year.
• Children ages 5 to 14 account for nearly 40 percent of all sports-related injuries treated in hospitals. On average, the rate and severity of injury increases with a child's age.
• Although 62 percent of organized sports-related injuries occur during practice, one-third of parents do not have their children take the same safety precautions at practice that they would during a game.
• Injuries associated with participation in sports and recreational activities account for 21 percent of all traumatic brain injuries among children in the United States.
• According to the CDC, more than half of all sports injuries in children are preventable.
• Among athletes ages 5 to 14, 28 percent of football players, 25 percent of baseball players, 22 percent of soccer players, 15 percent of basketball players, and 12 percent of softball players were injured while playing their respective sports.

Sports-related brain injury

As the statistics above note, 21 percent of all traumatic brain injuries among children occur while participating in a sport or recreational activity and half of all sports injuries are preventable. Of those sports-related brain injuries, some 300,000 are classified as mild to moderate traumatic brain injuries (TBIs). The mild to moderate TBIs are most often classified as concussions, which means that the patient has a temporary altered mental status as the result of a blow to the head. To understand what happens to the brain when a person has a TBI, we need to look at the anatomy of the skull and brain.

Skull Anatomy

The skull is not a single bone but rather a collection of bones that have grown together, encapsulating the brain. (See the diagram.) The boundary where the bones have grown together is called a suture, which insures a continuous, hard, protective case for the brain. An interaction between the brain and the skull due to a blow to the head is responsible for the trauma that causes a concussion.

Collision physics

When any 2 items collide, physics laws can be used to explain the forces and energy exchange between the items. The same is true for a blow to the head. Physics laws explain how the magnitude of the force imparted to the head result in motion of the brain inside the skull. Newton’s laws of motion explain the relationships among force, mass, and acceleration. Inertia and momentum help to explain the brain’s behavior within the skull. Remember Newton’s law of inertia states that a body in motion will continue in motion unless an outside force acts upon it. That includes your brain.

If you’re a football lineman at the line of scrimmage, standing still, waiting for a play, your brain is still. The quarterback calls the play, and you run head on into an opposing player. The acceleration and mass of your body imparts a force to the other player’s body, and vice versa. If there is head contact, helmets and skulls absorb some of the force to lessen the effect on the brain, exactly what they are designed to do.

The brain still receives a force that causes it to move within the skull. The greater the force, the more violent the brain movement. As the brain moves within the skull, it collides with the inner surface of the skull, a hard, rigid body. It’s the force of the brain hitting the skull that causes the concussion you or the player you collided with just sustained. Symptoms that you may be experiencing could include confusion, amnesia, headache, blurred vision, ringing in the ears, or nausea. Anytime enough force is applied to the head to move the brain, the danger of TBI and concussion is present.

Preventing TBIs and concussion

How can sports-related TBI be prevented? If you play a contact sport, are a spectator at football games, watch contact sports on TV, or wear a bicycle helmet, you know the answer. Well-engineered helmets are used to mitigate the effects of a blow to the head. How do engineers know how much force or kinetic energy a helmet must sustain to protect the wearer? Research!

Not all helmets are designed identically. Bicycle helmets are actually engineered to break under impact, dissipating the kinetic energy of the collision. Breaking reduces the kinetic energy of the impact from a fall from being transferred to the brain. Football helmets don’t break but do give a little and may have 3 or 4 layers of foam that absorbs energy. Every contact sport requires a specific set of engineered characteristics to help prevent TBI.

STEM: students as engineers

Students can engineer helmet designs too. First, know the anatomy of the skull and brain. You may even want to dissect a brain to examine specific structures. Just like the National Football League (NFL) and other sports-governing councils, research on helmet design and effectiveness needs to be completed prior to an initial design.

The Microsoft® Hacking STEM Project Building Models to Understand and Mitigate Brain Injury" is a STEM tool designed for students to engineer and test brain protection device designs. Students construct a model of the human brain and equip it with impact sensors to measure the effect of a head collision. Sensor data is collected, analyzed, and visualized with the Microsoft® Hacking STEM Project customized Excel® workbook. Prototypes are redesigned and reengineered in an iterative process until students have the data to support that their device provides protection from brain injury.

It’s all about students identifying and solving problems, engaging in scientific and engineering practices, and working as a team. In the words of Steven Johnson in Where Good Ideas Come From: The National History of Innovation, "The trick to having good ideas is not to sit around in glorious isolation and try to think big thoughts. The trick is to get more parts on the table."

Resources

American Orthopaedic Society for Sports Medicine. Stop Sports Injuries.org. Accessed October 23, 2019:
https://www.stopsportsinjuries.org/STOP/Resources/Statistics/STOP/Resources/Statistics.aspx?hkey=24daffdf-5313-4970-a47d-ed621dfc7b9b

Kowalski, Kathiann. 2016. ScienceNews for Students. “New Football Helmets Could Limit Brain Injuries.” Accessed October 23, 2019:
https://www.sciencenewsforstudents.org/article/new-football-helmets-could-limit-brain-injuries

National Center for Biotechnology Information, US National Library of Medicine. 2012. “Traumatic Brain Injury in Sports: A Review.” Accessed October 23, 2019:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3400421/

National Safety Council Analysis of US Consumer Product Safety Commission NEISS data. National Safety Council. Injury Facts®, 2017 Edition. Itasca, IL. Accessed October 23, 2019:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3400421/

NFL, NFLPA. 2019. "2019 Helmet Laboratory Testing Performance Results." Accessed October 23, 2019:
https://www.nflpa.com/news/nfl-nflpa-release-2019-helmet-laboratory-testing-performance-results

NFL Player Health & Safety. 2019. “Helmet Laboratory Testing Performance Results.” Accessed October 23, 2019:
https://www.playsmartplaysafe.com/resource/helmet-laboratory-testing-performance-results/

SpinalCord.com. 2016. "Infographic: 10 Shocking Sports Injury Statistics." Accessed October 23, 2019:
https://www.spinalcord.com/blog/infographic-10-shocking-sports-injury-statistics

US Department of Health and Human Services. 2001. "Sports-Related Recurrent Brain Injuries—United States." Accessed October 23, 2019:
https://www.cdc.gov/mmwr/preview/mmwrhtml/00046702.htm

Verywell. 2019. "Differences Between a Head Injury and a Brain Injury." Accessed October 23, 2019:
https://www.verywellhealth.com/head-injury-or-traumatic-brain-injury-4135406