NEW YORK – The NWSL and the league’s players association have officially joined Project ACL, a research initiative launched by global soccer players’ union FIFPRO in 2024 to study ACL injuries in the women’s game amid growing concern from athletes.
Both the NWSL and NWSLPA will work in tandem with FIFPRO as well as Project ACL’s existing partners, league sponsor Nike and the U.K.’s Leeds Beckett University, to further an industry-wide understanding of ACL injuries. The project will see researchers send a questionnaire to the medical teams at all 16 NWSL clubs, as well as conduct player interviews in a years-long process to collect information on physical performance metrics, workload and injuries in the hopes of improving an industry-wide understanding of a topic that has only received limited scientific research.
FIFPRO initially launched the project in 2024, firstly in conjunction with players in England’s Women’s Super League, though the NWSL offers unique areas of focus that will allow researchers to develop a broader understanding of ACL injuries.
“Obviously travel is a big one,” Dr. Alex Culvin, FIFPRO’s director of women’s football, said at an event at Nike’s headquarters on Tuesday. “Domestic travel is huge. We know that’s very burdensome for players. The calendar, when it’s played, it’s not traditionally played like a European calendar so the timing of the league is different meaning that international tournaments, rest periods, all of that [is different], and I think the way that the game is played is different. I think in Europe, we have a focus more on ball retention historically, and I think you see now teams in the NWSL adopting different styles of play, but there’s a lot more transition in the game. The players here are a lot more athletic, I think, than you find in Europe and so I think those factors will be important to consider all the way through the project.”
Factors outside of the NWSL’s control also play a big role, according to the league’s vice president of sporting Sarah Gregorius.
“The pathway to professional is very different in the U.S., in the NWSL, than what you see in England where you have much more standardized academies,” she said. “For example, here you have interaction between the youth ecosystem and then into college or not into college, so I do think that’s also a very important difference from what you typically see in England for the pathway to the top division versus what you see in the NWSL. The other interesting factor you see in the NWSL — and it’s probably the influence of college — is that the players are older here. The average age of the NWSL is higher than what you see in the WSL.”
Researchers are not simply searching for cause and effect in their findings but are instead looking at the intersection of the various topics of interest.
“We know travel is completely different and time zones and everything, but then it’s: What impact does that then have on fatigue, recovery, regeneration for players?,” Leeds Beckett University’s Dr. Stacey Emmonds said. “Again, it’s looking at that broader interaction between the contextual factors in the NWSL, but how those factors also interact.”
A player-focused project
Project ACL plans to put players at the center of their process, their years-long concerns acting as the impetus for the launch of the study two years ago. The women’s game has made many strides in recent years thanks to increased attention and investment, including in medical departments and resources at the club and national team level. Research on ACL injuries in women’s soccer, though, is lacking, much as medical research on women as a whole is.
“When we were [at the] Washington [Spirit], we had one medical person, a trainer, and that was it,” Jordan Angeli, a player turned broadcaster, said. “If we needed help with anything else, we’d have to make an appointment somewhere else and travel in the [Washington metropolitan area] to try to get to our [physical therapy] appointment somewhere across the city … We also were sharing facilities in the beginning. We were in what was like a gym, a local gym, and we were in just this [rinky-dink] locker room that we called ours, but now they’re building $130 million facilities for these players to train in.”
Players may have access to better resources these days, but the demands of the game are different these days. New competitions have been introduced to the NWSL’s ecosystem in recent years – the second-ever season of the Concacaf W Champions Cup is currently underway, while Gotham FC took part in the inaugural FIFA Women’s Champions Cup in January and have already qualified for the first edition of the FIFA Women’s Club World Cup slated for 2028. Fixture congestion has increasingly become a topic of conversation, forcing new questions of the growing medical teams elite players work with these days.
“Demand for us to play more games should never go away,” Crystal Dunn, the recently retired U.S. international, said. “We should be continuing to push for these opportunities for players to have more visibility, to be able to play multiple games, and I think now it becomes: What does load management look like? People speak about load management. Doesn’t mean players can’t play, but it does mean that there has to be more of a proactive interest in getting players the rest they need, maybe throughout the week, but still be able to be available for games.”
The wide-ranging study will allow researchers to provide more useful information to players and medical teams alike, as well as other decision-makers and onlookers in women’s soccer. That will include testing certain popular hypotheses – and mythbusting, if required.
“I think player education is huge and that has to be an embedded thread throughout the project, and the challenge we see a lot at the moment is a lack of understanding, or rather a miseducating of players,” Emmonds said. “One example is the menstrual cycle. It’s common when we talk about player injury or when we talk about performance, the first thing you hear about is the menstrual cycle, so if you talk making things female-specific, everyone will straightaway go [to] the menstrual cycle. It’s not to dismiss that [as] an important consideration but we know there’s a lot of education needed around that … There’s players who perform those actions, perform every day on their period and perform to the highest level — set world records, win World Cups, do everything but because of the media narrative we have now, we always hear about when a player does their ACL on their period. You never hear about, ‘She’s on her period, but she just won the World Cup.'”
A holistic view of the factors around ACL injuries could also reveal unexpected insights that will improve professional standards across the board.
“When we get to the end of it, and there are findings, and there are recommendations, I think the implementation of those recommendations is going to be massive,” league veteran and NWSLPA deputy executive director Tori Huster said. “That’s going to be a very critical piece to this. Although we have minimum standards set by the [collective bargaining agreement], if this project calls for above and beyond those minimum standards, I really, really do hope that can be something that’s implemented.”
The retired professionals at Tuesday’s event strongly encouraged the NWSL’s current player pool to participate in the project because they are ultimately the people with the relevant lived experiences – and the biggest benefactors of meaningful research.
“I think it’s important for players of this younger generation to understand if you don’t use your voice, someone will take it from you,” retired NWSL veteran Merritt Mathias said. “There will be someone that drives the narrative that isn’t yours, that doesn’t benefit you. That is just the truth and from my experience working with the PA and sitting at the table across from people that want the same as you but in different ways, if you are not vocal in those moments, if you are not pushing, if you are not asking, if you are not causing friction, you’re doing yourself a disservice because ultimately, this is a big business. Ultimately, the business will go on if you never make it back from an ACL injury. That is the truth.”
