Solving the ACL Injury Crisis in Women's Football
The need for action is at the junior level to tackle the problem at source
The number of teams missing their star players due to ACL injury as they contest this year’s women's (soccer) football world cup has put this issue firmly in the spotlight. It has been suggested that ACL injury may even prove to be a decisive factor in the outcome of the tournament. The commentary and calls for action in the press has centred on two distinct themes. Firstly, there has been much clamour on the urgent need for more research to shed light on the issue. The other claim is that the higher rates of ACL injury and worse outcomes in women’s football reflects a disparity in the support provided to professional female players in relation to the men’s game. Here I will dispute both of these conclusions. I will argue instead that the origins of the present injury crisis trace back years before these players ever reach the senior ranks.
First, let us deal with the popular claim that the higher ACL injury burden in women’s professional football is simply because they lack the support provided to their male counterparts. In short, this does not reflect the current reality on the ground. Whilst this has not always been the case, in the professional era the specialist support and training provided to female players at senior level is better than at any other time in history. The players currently sidelined with ACL injury come from professional clubs across Europe and North America that boast full-time sports science and medicine staff. None of this serves to explain why the ACL injury crisis in professional women’s football should be happening now.
The contention that higher ACL injury rates among female players simply reflects a disparity in support is similarly dubious when we examine the tiers below the senior professional level. The NCAA system perhaps provides the most direct comparison, as the support and off-field training provided to female collegiate players is at least on a par with men’s collegiate soccer (the women’s game is arguably more prestigious than the men’s). Yet despite comparable support and various injury prevention initiatives specifically aimed at female athletes over the past two decades, injury rates among female collegiate players have remained stubbornly elevated relative to males.
The claim that research is lacking is similarly spurious. Anterior cruciate ligament (ACL) injury is among the most researched sports injuries over recent decades - and females are the commonly featured cohort in those studies. Naturally, more data are always welcome, especially contemporary data featuring elite-level performers. All the same, there's plenty of information that provides insights into the reasons for the increased relative risk, mechanisms for injury and the key objectives for preventive measures and rehabilitation for female team sports players. Decades of research and a sustained focus on the need to reduce ACL injury among female athletes has seen numerous initiatives and countermeasures that have been extensively reported.
Non-contact ACL injuries most commonly occur when performing certain activities, such as pivoting, landing, stopping and changing direction - all of which feature prominently in football. Numerous studies demonstrate that when female players perform these activities they are more likely to exhibit biomechanics that place them at elevated risk of injury to the ACL. These biomechanical risk factors start to become apparent as girls begin puberty and can be traced back to cascade of changes that occur around this time. This helps to explain why preventive training is more efficacious the earlier and closer to puberty it is implemented. The ’tween years represent the best window for intervention as this offers the best opportunity to address these biomechanical risk factors before they take root.
There is no lack of empirical data to inform interventions or countermeasures. This is clearly not the issue. The failure to make a meaningful impact in reducing incidence of ACL injury and rates of reinjury in women’s football and women’s sport in general comes down to more fundamental issues of strategy and implementation. The focus on allocating more resources at the senior professional level is likewise misplaced.
Rather than benefiting from greater access to training and support, what is closer to the truth is that the boys are simply more able to get away with a lack of extensive off-field training during the junior years. For boys, puberty brings free gains in strength, lean mass, power, speed and endurance. Girls are not so lucky. Not only are they not blessed with free gains, things actually become harder (in the absence of training) as girls tend to gain mass without concommitant gains in strength and their longer limbs mean they are operating at more of a mechanical disadvantage. Without addressing these issues in a timely fashion it becomes inevitable that girls will be more susceptible to injury during their teenage years and into adulthood.
Increasing the capacity to develop force (i.e. strength) is critical to provide girls with the capability to adopt less risky biomechanics. To reinforce the point, the data indicate that strength is a bigger contributor to relative ACL injury risk for females compared to males. Beyond global force-generating capacity, female athletes also exhibit specific deficits in their ability to develop force rapidly and resist forces under higher speed conditions. All of this helps to explain why female players are more susceptible to ACL injury as they perform high risk movements under live conditions during practices and games.
What all of this points to is that dedicated physical preparation is essential for girls at junior level. It is established that early intervention dramatically increases the probability of a positive outcome, so regular training should commence in early adolescence (ideally before) and continue thereafter. What is also evident from the research is that this must include strength training and other high-force activities such as plyometrics to be effective. Far from being common practice, this almost never happens as things stand - hence why we continue to see the elevated rates of injury among female players at high school, collegiate and senior-level.
Rather than allocating resources on further research and boosting the support that is already available to senior professional players, it would be much better to invest in providing training for young players at the grassroots level. Addressing the specific deficits and tackling the biomechanical issues at source during this pivotal phase in their development will prove far more effective at reducing ACL injuries in women's football at all levels of the game. Aside from the greater efficacy of early intervention, many players suffer injury prior to reaching the professional ranks, which inevitably makes them more susceptible to injury (previous injury being the biggest predictor of future injury). Tackling the problem at source and preventing injuries during the junior years is the best way to have a measurable impact on injury rates at the senior professional level.