NOCSAE-Driven Research Led to Breakthrough in Puzzling, Fatal Sports Injury

It is with pride that NOCSAE welcomes the start of each new lacrosse season. One of the impacts of NOCSAE-funded research has been to make the sport of lacrosse safer, and there’s an interesting story behind how this developed.

Mysterious deaths among young athletes 

We were already studying injuries caused by concussive hits before news stories brought it to the public’s attention that athletes were sometimes dying from what appeared to be a minor blow to the chest. These events were thought to be rare. But each death was not only a tragedy because it was a life lost — the circumstances of the fatalities were stunning. Often the case involved young athletes, with no underlying health conditions, who collapsed on the playing field. Most efforts to resuscitate were unsuccessful. 

The syndrome had a name, commotio cordis (CC), which means “disturbance of the heart,” but no one could explain why only some hits over the heart were fatal, nor why so many of the victims were adolescents. Adding to the mystery was that there was no physical damage to the heart. 

Joining forces, and a major discovery 

More incidences of CC began to be reported in the late 1990s after an article in the New England Journal of Medicine raised awareness of the phenomenon. Dr. Barry Maron, one of the article’s authors, would later take on an important role in NOCSAE’s efforts against CC. 

Meanwhile, NOCSAE-funded research efforts were making headway. Good stories have heroes, and Dr. Mark Link turned out to be one of the heroes of NOCSAE’s commotio cordis story. He is an expert in electrophysiology and specializes in abnormal heartbeat patterns. He was chosen to spearhead our research efforts because he had been making impressive progress on the problem in his lab at Tufts University. 

Dr. Link made a key discovery, answering the most puzzling question about CC. Why were some hits to the chest lethal even though most were not? He found that only hits striking at a critical moment in the cardiac electrical cycle cause CC arrythmia. Force transferred from a striking ball, through the chest wall to the heart, interrupts the heart’s cadence, sending it into a disorganized rhythm that fails to circulate blood through the body. Because of Link’s discovery, the world now knew how an ordinary-seeming ball strike can cause death. 

Turning point 

In 2000, NOCSAE received a call from a mother who had just lost her 14-year-old son to commotio cordis during his first high school lacrosse game. This tragedy became the inflection point, resulting in NOCSAE’s bringing to bear all its resources to attack CC. 

Beyond the lab, onto the playing field 

NOCSAE’s role in athlete safety is to write performance standards for athletic equipment. Sports equipment manufacturers design their products to perform to these standards. NOCSAE’s CC challenge was to develop a method for testing protective equipment against the conditions that cause this injury. There was still a lot of work to do. 

Dr. Nathan Dau’s work in the Sports and Ballistics Lab at Wayne State University for NOCSAE yielded an important leap toward developing such a standard. He created a biomechanical chest surrogate to model, and measure, the human response to ball impacts.  

In a series of further studies for NOCSAE, Dr. Link found that only perpendicular hits over the center of the heart cause CC. He also identified the injury prevention threshold, which is a measure of how much impact force is necessary before commotio cordis is triggered. This is a key metric to test equipment performance. It is one of the measures manufacturer’s need to develop prototypes. 

Almost the end of the story is that, based on the research we funded, the world’s first CC standard was approved by the NOCSAE Standards Committee. ND-200: Standard Test Method and Performance Specification Used in Evaluating the Performance Characteristics of Protectors for Commotio Cordis. NOCSAE also funded the establishment of a national registry to track CC cases, which was organized by Dr. Maron. As a result, it is now known that 15 – 25 athletes die from CC annually. 

This year youth, high school, and collegian lacrosse players will gear up in CC protectors manufactured to meet NOCSAE’s standard. The rest of the story is that these protectors must fit properly, according to manufacturer instructions. It’s also important for AEDs to be available on the field in case of emergencies. 

Annually, about 66% to 80% of CC cases occur in adolescents. It’s thought that this is because their chest walls are still somewhat pliable and more vulnerable to impacts near the heart. As we age, the chest becomes stiffer. Cases occur most frequently in sports with projectiles, such as baseball, softball, lacrosse, and hockey. Although, it can also occur from hits with a fist or foot, as in martial arts. 

The story of how NOCSAE developed the standard to lower CC risk spotlights our continued leadership in sports safety research.