4/26/20 Offensive linemen

Purdue offensive linemen set up in three-point stances. According to two Purdue researchers, this stance is dangerous because it puts the player's head as the first point of contact. A modified two-point stance in which a player is more upright can eliminate the number of blows he receives to the head. 

Purdue professors Eric Nauman, of mechanical engineering and medical sciences, and Thomas Talavage, of electrical and computer engineering and biomedical engineering, aren’t new to concussion research.

Their study on the head trauma of Jefferson High School football players was featured in a concussion issue of Sports Illustrated in November 2010. In the study, 23 Bronchos’ helmets were fitted with sensors made to measure the level of impact a player receives to the head with each collision, and the frequency of hits they take. Those players were administered ImPACT tests — electronic exams that test memory and concentration — before and after practices.

Their findings were exactly what they expected, according to the article. Players who received more hits to the head performed worse on their ImPACT tests than those who received fewer hits, regardless of whether those players currently had concussions.

From that, Nauman and Talavage deduced that repeated blows to the head can be dangerous for the brain, regardless of whether a concussion is present, per the article. They also found that the players who received the most blows to the head in practices and games were offensive linemen.

Eight years later, the research duo teamed up with Paul Auerbach, a professor in the Department of Emergency Medicine at Stanford University. Together they conducted a new study to try to reduce the amount of head trauma offensive linemen suffer.

Their solution: Require offensive linemen to start plays in upright, two-point stances rather than traditional three-point stances.

“It was actually Dr. Auerbach that came up with this idea that the stance could really affect the number of hits that these linemen take,” Nauman said. “At that point we’d been studying head injuries for about eight years and we knew that linemen take a hit almost every play.”

A three-point stance for an offensive lineman can vary, but generally a player will stand with feet slightly wider than shoulder width apart, and squat down so their knees make 90-degree angles. Then, the player will lower his chest so it is close to parallel with the ground, and put one hand down on the ground. This allows the lineman to fire out forward with a lot of force.

The revised stance Auerbach suggested would instead have a lineman with his chest up and pointing outward, his back at an angle more than 45 degrees to the ground.

“The emphasis was on not having your head down to begin with,” Talavage said. “Making sure your weight was back, you’re a little more upright, essentially eliminating that kind of launch guys get at the line when the O-line and the D-line slam into one another.”

With no financial backing, Nauman and Talavage said they flew to San Diego to set up their study on 78 Spring League football players in July 2018. The Spring League is a league for college graduates to play to get more experience and exposure in preparing for the NFL. The duo were accompanied by Taylor Lee, a then-graduate student at Purdue researching on fellowship under Nauman in the School of Mechanical Engineering.

Once there, the research team used sensors in players’ helmets to record the number of blows each player took to the head, and it asked offensive linemen to start plays in an upright two-point stance. The team then analyzed video of practices and cross-referenced the helmet sensors to see which players adopted the revised stance and measured the number of blows to the head they took depending on that variable.

The study had a variety of those who started in three-point stances and two-point stances, so the researchers were able to see which starting position led to more helmet collisions.

“Every night, (Lee) had a whole hotel room where she had all the stuff laid out and she had sensors everywhere, and computers and stuff,” Nauman said. “When we got back, for the next two months, she and a bunch of undergrads just crunched the data.”

Each night for a week, Lee said she analyzed data from the sensors before they were reapplied to players the next morning for further testing.

“The week itself, it was just one thing after another,” Lee said. “You have to set up and then you have to deploy the sensors, then you have to get them back, download them, rinse, wash, repeat.”

After the data had been analyzed, the team concluded that offensive linemen who start in an upright stance receive 40% fewer blows to the head than those who start in a three-point stance.

“This is the first time someone has ever quantitatively evaluated one of these inventions,” Nauman said. “Not just anecdotal evidence. This was, ‘We think there’s an issue here, let’s go test it, let’s see if we can make recommendations.’”

A rule forcing offensive linemen to play from an upright position while defensive linemen remain in three-point stances could lead to a disadvantage in the run game, but the team hopes the rule can apply to both sides of the line in the future.

“Ideally, the original hope was that we’d also have the D-line in a two-point stance,” Talavage said. “That requires a little more of a workaround with the coaches (and) the players.”

While the stance may affect an offensive lineman’s ability to fire out forward with a lot of force, Nauman pointed out that the change should not significantly alter a team’s play-calling and offensive schemes. He said most players and coaches involved in the study reacted positively to the suggested rule change.

“We generally got good responses from the coaches,” Talavage said. “The players were quite intrigued by it, actually.”

While an official rule change at the college or professional level may not be a realistic possibility for another few years, the team believes the research it is doing can be extremely beneficial to the overall safety of the game.

“Between doing this, and then some minor changes to equipment, honestly, I think we can take a lot of the fear of injury out of this game,” Nauman said. “It really does not have to go like this.”

Now, the research team is working with high school and college coaches to analyze head impacts on players and make suggestions to improve safety throughout the season.

“We’ve got some collaborations we’re doing with Dartmouth (College) where we can evaluate some of their training techniques and get some data from them,” Nauman said. “That’s one of the most progressive teams, in the sense that they don’t allow any tackling at all in practice, and that actually makes a ton of sense to me.”

Dartmouth’s approach is closer to the current approach of the NFL, which allows only two full-contact practices per week. The less contact players have in practice, the less likely they are to suffer brain trauma.

“If we can get coaches on board with that,” Nauman said, “and the stance, and design better helmets, this isn’t a scary game anymore.”

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