Richard Greenwald discusses new technology to monitor head injury.
Photo: Ernie Branson
Homer Simpson hits his head, sees stars and everyone laughs.
But head injuries are no laughing matter for kids who play contact sports. Nervous moms and dads want to know: are helmets safe?
“Research and testing led to the development of helmets effective in preventing traumatic brain injuries,” said Richard Greenwald, president of Simbex. The same cannot be said for relying on helmets to prevent milder—but still serious—traumatic brain injuries (MBTIs), such as concussions.
“Most current helmets were not developed specifically for reducing risk of concussion because we’re only now learning how they might,” said Greenwald in his Apr. 17 lecture “Biomechanical Basis of Concussion: Monitoring Head Impact in Sports,” part of the NICHD Director’s Lecture Series.
A concussion is a serious head injury that can result from a hit or jolt, from sports activities, accidents, falls or other trauma. Annually, about 1.6 million people sustain recreation-related concussions or other MTBIs. Most people who have a concussion don’t lose consciousness. Although symptoms may include nausea, vomiting or convulsions, you can havea concussion and not realize it. Some people, including athletes of all ages, are never diagnosed and risk further injury. Research has linked repetitive head injuries to long-term chronic brain injury, including early onset dementia.
Despite the frequency of concussions, little research had been conducted on head impact exposure until recently. Starting in 2001 with the support of NICHD’s National Center for Medical Rehabilitation Research, Simbex developed the Head Impact Telemetry System (HITS). With this technology, Greenwald and his colleagues have been working to supply the needed data. They have monitored more than 1.8 million head impacts on athletic fields and hockey rinks.
“Our goal is to prevent short- and long-term effects of repetitive impact exposure,” Greenwald said. With information supplied by HITS, he and his colleagues are undertaking the research to move down the field toward that goal.
HITS transforms a helmet or headgear into a head-impact monitor and provides real-time, continuous, on-field data collection. A package with impact sensors, a processor and a transmitter are fitted inside the helmet. A microprocessor-based data collector can then receive impact data continuously from helmets up to 100 meters away. The collector stores all key impact signatures—frequency, location and severity—with a time stamp for future analysis.
As Greenwald and his partners across the country tested and collected data using HITS from high school, college and professional athletes, they knew they were breaking new ground. “This research for the first time defines head impact exposure—‘how often, how hard and where’—as a function of gender, player position and practice-versus-game and allows us to correlate that data with clinical history surrounding diagnosed concussion.”
At the same time, Greenwald and his colleagues understand that even as they race to apply biomechanical science to real-world safety needs, more research is needed.
“We need to better understand brain injury mechanisms, interactions with equipment and the circumstances surrounding head injuries,” he said.
Spotlight on College Sports
Richard Greenwald’s research found that in collegiate football:
- Individual athletes have sustained more than 2,000 head impacts in a single season.
- The magnitude of the impact is influenced most by playing position and the location of the impact. For example, running backs sustain overall the highest magnitude impacts to the head.
- Nearly half of the 120 diagnosed concussions in the study resulted from hits to the front of the head.
And in a comparison of men’s and women’s collegiate hockey:
- Male players sustained twice as many impacts as female players.
- There were no differences between genders when comparing the location and severity of hits.