The National Women's Soccer League has joined the Women's Super League and the global players' union FIFPRO in a three-year research initiative aimed at reducing anterior cruciate ligament injuries in women's soccer.

FIFPRO initially launched Project ACL in 2024 in conjunction with players from England's Women's Super League. The initiative now expands to include the NWSL and its players association as research partners.

ACL injuries occur between two and six times more frequently in women than men. While biological differences have traditionally been cited as the primary cause for this disparity, the research project takes a broader approach to understanding contributing factors.

The initiative examines environmental factors that may influence injury rates, including pitch quality standards, weight room access, schedule congestion, and equipment quality such as cleats. This holistic approach represents a shift from focusing solely on biological explanations for the higher injury rates among female players.

The timing of the expanded research comes as injury concerns affect players across the sport, with the upcoming World Cup less than two months away creating additional pressure for athletes recovering from various injuries.