Ankle Sprains Are Plaguing the NBA. Big Data Wants to Help

According to Hashtag Basketball’s database, which tracks the causes of the 4,000-plus times NBA players have missed games since 2010, only one injury has been a more common culprit than “sprained right ankle”: sprained left ankle. Over that time, ankle injuries cost players a cumulative 15 years’ worth of action. In any season, 25% of NBAers will suffer an ankle sprain.

Every basketball fan is familiar with the painful sight of watching their team’s best player sitting on the floor, grimacing, holding his foot as a fanbase holds its breath. But despite all the time and money lost to ankle injuries, they’ve proved frustratingly unavoidable … for now.

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Within the last year, the NBA, with support from the players association, has launched an internal initiative focused specifically on ankle injury reduction, hopeful that big data can keep stars on the court more often.

That step was only made possible by the ones that came before—notably, the establishment of a league-wide electronic medical record system a decade ago combined with a yearslong partnership with epidemiology company IQVIA.

“The real foundation for injury prevention is making sure you have a good database, and you have a good way of analyzing that data,” NBA director of sports medicine Dr. John DiFiori said.

Now, the initiative includes an advisory board made up of additional MDs and PhDs, three working groups, and a half-dozen specific projects.

For instance, the NBA is looking to work with university scientists to calculate the various impacts on the ankle of different shoe structures, court compositions, taping methods, etc. Another project involves reviewing video of past ankle injuries to record the precise movements that lead to tissue issues. Additionally, the league has plans to perform biomechanical assessments of players four times a year.

In each case, the goal is to generate even more data—on healthy ankles, hurt ones, empty shoes, different floors—to identify what tweaks could be made to prevent, well, tweaks.

The root of the problem is straightforward if gruesome, as the bands of tissues that connect bones (ligaments) tying the foot to the leg are stretched or torn when put under sudden strain. Most often, it’s the ligaments on the outside of the ankle that are injured, with repeated injuries causing the ligaments to sometimes appear on images like a disintegrating sweater. But beyond that outline, little is known about what causes those now familiar moments of agony.

“We focused on ankle injuries because they’re common in basketball … and in some ways, they’re not as well studied as other more high-profile injuries like ACLs,” NBA SVP for player matters David Weiss said. “It’s a place where we really thought … we might be able to make a bigger difference.”

Despite all the work being done, DiFiori said the league is still in the early stages of understanding the issue, not yet ready to begin establishing goals around how much of a dent it can make in the epidemic. Creating standardization around how the injuries are categorized would represent a leap forward in itself, as would recommending small changes to the way basketball players prepare for games at all levels of competition.

“When everybody’s kind of talking the same language, that actually is a big step for sports medicine,” DiFiori said.

Since 2019, the NBA has leveraged a partnership with machine learning experts to further analyze its data, looking for connections between injuries, travel times, player tracking data and so on. Those inputs will improve next season too, when the league moves to a far more precise tracking system built by Hawkeye.

The NBA Launchpad program, a league initiative to source, evaluate and test emerging technology, has also been pulled into the fight. Last year, the league selected Berlin-based adaptive ankle brace maker Betterguards to participate in its first cohort. Already in use by multiple NBA players, as well as roughly 2,000 pro and amateur athletes in other sports, the company’s brace uses an embedded piston to allow freedom of movement up until a critical point, when the ankle becomes stabilized in a more rigid fashion. It sells for $199.

“The biggest thing we need right now is just people understanding this technology exists,” CEO Tony Verutti said. “Being brand new, being from Germany … we’re just trying to drive awareness and education.”

Betterguards’ ultimate vision is cutting down on the millions of ankle injuries occurring around the world (roughly 2 million take place in the U.S. alone each year). The hope is that improved brace tech can also limit the severity of issues when they do arise.

“If we can have an ankle sprain go from missing four weeks to missing one week, that’s a huge win, and I think that’s where Betterguards is really going to set itself apart,” said Betterguards advisor Keke Lyles.

As the Golden State Warriors’ head of performance from 2013 to 2015, Lyles has spent plenty of time thinking about the problem.

During the 2011-12 season, Steph Curry suffered five ankle sprains while playing in only 26 games. Offseason surgery helped, but so did a completely new workout regimen, which focused on developing core, hip and upper leg strength to take the load off his ankles.

Curry’s team also credits his Zamst ankle braces, custom Under Armour shoes and the Warriors’ advanced fatigue monitoring setup with keeping him largely upright since. (Lyles also made sure Curry took a few training days off to unwind.)

Curry’s weren’t the only ankles keeping Lyles up at night. Numerous other injuries, he said, are often traced back to running and jumping form. Force plates and gait-tracking technology have become increasingly common to identify possible improvements before disaster strikes.

“Our kind of joke is, ‘Things go bad when foot hits the ground,’” Lyles said. “And obviously, the foot hits the ground over and over and over. So everything starts there.”

Despite increasingly smart interventions, the incidence of ankle injuries hasn’t shrunk, instead fluctuating year to year. But Lyles believes the NBA is on the precipice of change.

“We have the data to kind of say, ‘Okay, we need to do things differently’,” he said. “Now, we’re starting to do things differently. I think this next decade is going to be where we start to really see a decline.”

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