How Hormones Might Be Putting Female Athletes at Higher Risk for ACL Injuries

Personal photo of me in 2021 

Last week, I talked about how mental health can affect injury and recovery, so this week I wanted to narrow it down and talk about women in sports and how hormones can play a role in injuries. I’ve always known ACL tears are more common for female athletes because every teammate I have had, for the most part, has torn their knee, but nobody ever really explained to me why that was the case. So many coaches have said it was “landing wrong” or “weak glutes or other muscles,” and then move on. After tearing my ACL once and my meniscus multiple times, I really want to figure out what’s actually going on both mentally and physically in our bodies overall when this happens, instead of just brushing it off. My main question this week is: Do hormones during the menstrual cycle affect ACL injury risk in female athletes, and if so, why isn’t this talked about more?

I found a systematic review by Herzberg and others that helped me with the question I asked this week. The authors who did the study had 21 studies and over 68,000 participants to see if changes in estrogen levels during the menstrual cycle change how loose the ACL becomes.  (Herzberg et al., 2017) When ligaments are looser, the knee can shift more, and everything is weaker/more tired, which could increase the risk of injury.  (Herzberg et al., 2017)

One of the biggest things I learned from this research article is that the ovulatory phase (about halfway through the cycle) might be the most dangerous time to play sports, especially for cutting, landing, or pivoting, because estrogen levels are higher. According to the article, “The literature suggests an association between hormonal fluctuations and ACL injury” (Herzberg et al., 2017). I picked this quote because I remember when I tore mine, I was right around the same point in my cycle. So were two of my teammates who tore theirs the same year. Could there be a coincidence? Maybe, but this research makes connections that I can relate to, and the same with my teammates, and that is hard to ignore and just blows it off as that. 

Another big thing I took away from it is that oral contraceptives ( which are birth control) might actually help lower ACL risk. The article says, “Recent studies have suggested that oral contraceptives may offer up to a 20% reduction in risk of injury” (Herzberg et al., 2017). I had heard rumors about this when I grew up from older girls and their experience with birth control and injuries, but seeing data that shows that it actually reduces injury honestly made me upset because if this is real, I could have benefited from it before my injuries. Why do female athletes not learn about this until after the injury?

The last important thing that was talked about is that the authors said that knee laxity was “significantly increased in the ovulatory phase compared with the follicular phase” (Herzberg et al., 2017). This basically means that estrogen might loosen ligaments in your knee. Looser ligament equals unstable knee, which then equals a greater chance of tearing the knee, especially when it is non-contact movements.

Picture my mom took for my first surgery in 2024

Every ACL tear and meniscus tear I have had, no one hit, tackled, or tripped me. My knee just kind of gave out. I always beat myself up over it because how could it be that easy, since my legs were super strong and muscular? But when I look back at that time in my life, I was training intensely 6 days a week, which wasn’t a new thing since I was little, since I played at such a high level, but it was also right around the same hormonal phase in my cycle that the article talks about. Could I have prevented at least one of my surgeries if I knew this information? Why didn’t anyone teach this if we had this info?

I think if athletic programs tracked menstrual cycles the same way they track how much we run or our heart rates during practices and games, athletes could have smarter training plans instead of just hard 6 days a week practices. Coaches could take heavy cutting drills out during these high-risk cycle times and instead have players do stability exercises. I think something as simple as that could save careers and the mental/physical stress of injuries.

I am not sure why this problem isn’t talked about because female athletes deserve more than “knee injuries just happen.” This discovery is real science about the body, hormones, timing of the cycle, and biology of women, yet it is underground.

Here’s a short video talking about this topic https://youtu.be/xpAWcGFcG5Q?si=6jHwl2EVTB2ORkoi

New Questions for Next Week

1. How can coaches talk about cycle tracking without making it awkward?

2. Should athletic programs have sessions on birth control as injury prevention?

3. Why hasn’t the NCAA injury prevention used this research already?

This research helped me, and I'm sure a lot of other female athletes, not feel crazy. It could ease our minds that maybe there is a biological explanation behind why we are tearing our ACLs more than men. I think if we can spread this information and do more research, maybe future female athletes won’t have to go through five knee surgeries to step back onto the field.

Citations

Article link: Herzberg, S. D., Motu’apuaka, M. L., Lambert, W., Fu, R., Brady, J., & Guise, J.-M. (2017, July 21). The effect of menstrual cycle and contraceptives on ACL injuries and laxity: A systematic review and meta-analysis. Orthopaedic Journal of Sports Medicine. https://pmc.ncbi.nlm.nih.gov/articles/PMC5524267/ 

Video link: KING 5 Seattle. (n.d.). Link between menstrual cycles and ACL tears.

https://youtu.be/xpAWcGFcG5Q?si=6jHwl2EVTB2ORkoi